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Copyright © 2008 by the Wound, Ostomy and Continence Nurses Society J WOCN ■ March/April 2008 169

WOUND CARE

An Innovative Enterostomal TherapyNurse Model of Community WoundCare DeliveryA Retrospective Cost-Effectiveness Analysis

Connie Harris � Ronald Shannon

PURPOSE: A Canadian specialty nursing association identifiedthe necessity to examine the role and impact of enterostomal(ET) nursing in Canada. We completed a retrospective analysisof the cost-effectiveness and benefits of ET nurse–driven re-sources for the treatment of acute and chronic wounds in thecommunity.

DESIGN: This was a multicenter retrospective pragmatic chartaudit of 3 models of nursing care utilizing 4 community nursingagencies and 1 specialty company owned and operated by ETnurses. An analysis was completed using quantitative methods toevaluate healing outcomes, nursing costs, and cost-effectiveness.

MAIN OUTCOME MEASURES: Kaplan-Meier estimates were calcu-lated to determine the average time to 100% healing of acuteand chronic wounds and total nursing visit costs for treatmentin a community setting. Average direct nursing costs related tomanagement of each wound were determined by number ofnursing visits and related reimbursement for each visit. AMonte Carlo simulation method was used to help account forcosts and benefits in determination of cost-effectivenessbetween caring groups and the uncertainty from variationbetween patients and wounds.

RESULTS: Three hundred sixty chronic wounds and 54 acutesurgical wound charts were audited. Involvement of a regis-tered nurse (RN) with ET or advanced wound ostomy skills(AWOS) in community-level chronic and acute wound care wasassociated with lower overall costs mainly due to reduced timeto 100% closure of the wound and reduced number of nursingvisits. The differences in health benefits and total costs of nurs-ing care between the ET/AWOS and a hybrid group that in-cludes interventions developed by an ET nurse and followed bygeneral visiting nurses that could include both RNs and regis-tered practical nurses is an expected reduction in healing timesof 45 days and an expected cost difference of $5927.00 perchronic wound treated. When outcomes were broken intoET/AWOS involvement categories for treatment of chronic

wounds, there was a significantly faster time to 100% closureat a lower mean cost as the ET/AWOS involvement increased inthe case. For acute wound treatment, the differences in healthbenefits and total costs between the ET/AWOS and a hybridnursing care model were an expected reduction in healingtimes of 95 days and an expected cost difference of $9578.00 peracute wound treated. Again, there was a significant differencein healing times and reduced mean cost as the ET/AWOS be-came more involved in the treatment. The financial benefit tothe Ontario Ministry of Health and Long-Term Care is esti-mated to increase as the involvement of nurses with ET/AWOSspecialty training increases.

CONCLUSIONS: The greater the involvement both directly and in-directly of an ET/AWOS nurse in the management of wounds,the greater the savings and the shorter the healing times.

■ Background

The Canadian healthcare system is currently facing pres-sure to control healthcare costs while maintaining a highquality of care. There is an increased demand for homecare, which now includes both chronic and acute diseasemodels. Nursing visits and the cost of wound care dress-ings absorb a significant percentage of community health-care budgets, with wound care delivery accounting formore than 50% of nursing visits.1 Current research and

J Wound Ostomy Continence Nurs. 2008;35(2):169-183.Published by Lippincott Williams & Wilkins

� Connie Harris, MSc (c), RN, ET, Senior Clinical Specialist, Ostomyand Wounds CarePartners ET NOW Division, Kitchener, Ontario,Canada.� Ronald Shannon, MPH, Freelance Healthcare Economist, CliftonPark, New York.Corresponding Author: Connie Harris, MSc (c), RN, ET, Ostomy andWounds CarePartners ET NOW Division, Unit B 207-151 FrobisherDr, Waterloo, Ontario, Canada N2V 2C9 ([email protected]).

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170 Harris & Shannon J WOCN ■ March/April 2008

best practice has served as a catalyst for the development of“advanced” wound dressings over the past 25 years. The pro-motion of best practices such as moist wound healing maybe used correctly, incorrectly, or not at all. Lack of knowl-edge of best practice and inconsistencies in application mayresult in unnecessary daily community nursing visits, pro-longed healing times, frequent physician appointments,and hospital admissions due to complications. Healthcareorganizations need to understand and position the bestqualified healthcare professional who can provide leader-ship to maximize the direct and indirect management ofpatients with wounds. Today’s challenges are to make thebest possible use of limited human and economic resourceswhile ensuring the delivery of excellent patient care.

Research positively influences the choice of the besttreatment for a wound. Using meta-analysis, Heater andcolleagues2 studied the contribution of research-based prac-tice to patient outcomes, and reported that patients who re-ceive research-based nursing care make “sizable gains” inchanging their behavior to improve their health (behavioralknowledge), actual improvements in body functions (phys-iological), and emotional (psychosocial) outcomes com-pared with those receiving care that is not research based.

The Canadian Association for Enterostomal Therapy(CAET) was recognized as a distinct nursing specialty bythe Canadian Nurse’s Association in March 2007. Theassociation’s Enterostomal Therapy Nursing EducationProgram (ETNEP) is a postgraduate program for baccalau-reate prepared registered nurses (RNs) that provides spe-cialized and expanding knowledge and clinical expertisein managing skin, wound, ostomy, and continence care.Primary responsibilities of an enterostomal (ET) nurse areto assess, direct, deliver, coordinate, and evaluate individ-ualized patient care by measuring the responses andoutcomes to evidence-based management.

■ Purpose

As a concurrent activity with the process to develop spe-cialty certification, the CAET identified the need to exam-ine the role and impact of ET nursing in Canada. Thisstemmed from a need to market the ET specialty and to de-finitively demonstrate its value. However, the associationrealized that it did not have outcomes data to support therole. In 2005, the CAET partnered with a unique ET-ownedand ET-operated community nursing agency and a health-care economist to conduct a retrospective pragmaticanalysis of the cost-effectiveness and benefits of ETnurse–driven resources for the treatment of acute andchronic wounds in the community.

■ Methods

An analysis of treatment outcomes of patients with acuteand chronic wounds in the community by ET and regis-tered nurses with advanced wound and ostomy skills

(AWOS) was completed. A retrospective review of patientcharts was completed and quantitative analyses were usedto evaluate healing outcomes, nursing costs, and cost-effectiveness. Outcomes used to measure effectiveness ofwound management were (1) the time required for woundhealing, (2) time required for the patient to be discharged(healing discharge times), and (3) condition at discharge.Patient charts were reviewed from 4 community nursingagencies and an ET-owned and ET-operated communitynursing agency specializing in the delivery of evidence-based care of wounds.

Participating Sites Five nursing agencies in 2 local community care accesscenters (CCACs) participated in the study. All of thesenursing agencies provide community care under contractto the CCAC, which is funded under the Province ofOntario Ministry of Health and Long-Term Care. The 3general community nursing agencies who participated inthe Waterloo Region portion of the study did not have ETnurses or AWOS on staff, but worked collaboratively withthe specialty ET nursing agency. Referrals for consultationto the ET/AWOS agency utilized the following criteria,which were developed collaboratively with representativesof all nursing agencies and the CCAC (Figure 1).3

The general nursing agency in the Oxford-Region CCACused the acronym FUN to identify indications for anET/AWOS consultation. When applies to the clinical setting,“F” indicates the need to consult the ET/AWOS nurse whenthe frequency of dressing changes is not less than 3 times perweek within 4 weeks. “U” indicates the need to consult theET/AWOS nurse when the etiology of the wound is un-known, and “N” indicates the need to consult the ET/AWOSnurse if the size of the wound has not decreased by 20% to30% within 3 to 4 weeks of initiating treatment. These cri-teria were established by a joint CCAC collaborative initia-tive that several CCAC and service providers participated inacross the province and included a wound education com-ponent for the general visiting nurses.4

The visits by the specialty ET nursing agency were 50%ET and 50% AWOS. RN ETs did all of the admission visitsand would carry more complex clients than the AWOSnurses, but both groups are able to initiate wound carebelow the dermis, including sharp nonviable debride-ment. The AWOS works in collaboration with the ET nurseas needed, whereas the ET has a more autonomous prac-tice. Both groups inform the physician of care plans as avalued team member.

The model for care delivery for each of the 4 generalagency sites could include all of the following:

1. The “hybrid” model where the specialty nursingagency coordinated visits with RN and registeredpractical nurse (RPN) visiting nurses from other com-munity nursing agencies. Both RNs and RPNs studyfrom the same body of nursing knowledge. RNs study

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for a longer period of time, allowing for a greaterknowledge base in clinical practice, decision making,critical thinking, leadership, research, and resourcemanagement. RPNs study for a shorter period of time,resulting in a more focused body of knowledge in thesame areas.5 The RPNs’ scope of practice is broadlysimilar to that of a licensed practical or licensedvocational nurse in the United States.

2. The “ET/AWOS only” model where patients wereseen exclusively by the specialty agency.

3. The “RN/RPN only” model with no ET/AWOSinvolvement.

The model of care for the RN ET/AWOS agency could in-clude the first and second models as described above, withthe RN ET/AWOS either being the first to assess and treator being asked in after the general agency had admittedthe patient.

Sample Discharged charts representing all of the major woundetiologies seen in the participating sites between January 1,2006, and April 15, 2006, were reviewed. Additional dis-charged charts representing both the hybrid group and theET/AWOS group were obtained from 2003 to 2005. Wound

FIGURE 1. Triage for ET consultation Waterloo Region CCAC, 2005.4

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etiologies included surgical wounds, diabetic foot ulcers, ve-nous stasis ulcers, pressure ulcers, and other diabeticwounds. The goal was to have each of the 3 groups (hybrid,ET/AWOS, and RN/RPN) have a minimum of 20 charts fromeach wound type—surgical, diabetic foot, venous, pressure,other diabetic wounds, and other chronic wounds, with agoal of 140 for each group and 420 total charts.

■ Inclusion and Exclusion Criteria

Inclusion criteria included patients treated for a woundwith a documented etiology (surgical wound, diabetic footulcer, venous stasis ulcer, pressure ulcer, or other diabeticwound) and wound measurement documented over atleast 2 visits. Exclusion criteria included private referral,long-term care or acute care patients, less than 2 serialwound measurements, less than 2 visits, first visit made inan acute care facility, or other wound etiologies outside ofthe inclusion criteria.

■ Ethics Approval and Privacy Considerations

Ethics committee review and approval was obtained priorto data collection. Informed consent was not required be-cause this was considered a quality review process.However, 1 nursing agency requested patient consent tobe obtained and consents were obtained at that site.Patient identifiers were not revealed in the final report,and hard copy and computer data were secured at alltimes. All researchers and student assistants entered intoan agreement regarding patient privacy and confidential-ity, conforming to the regulations as outlined by Federaland Provincial Privacy Legislation in Canada.

■ Objectives

We sought to determine if there were significant differencesin time to complete wound healing, condition of the woundat the end of care, and wound etiology and time to end of carebased on the 3 care delivery models (ET/AWOS only, noET/AWOS care, and hybrid) defined previously. Specific studyobjectives were (1) to demonstrate outcomes of ET/AWOSnurse as compared with general visiting nurses for managingwounds in the community; (2) to determine the cost savingsand health benefits when an ET/AWOS nurse manages awound in the community setting; and (3) to provide a bud-get impact analysis of using ET/AWOS nurse services.

■ Data Collection

Patient charts were selected by etiology for the specialtyagency charts. The general nursing agency charts were col-lected as the patient was discharged, and later sorted basedon etiology by nursing student auditors who were trainedby the researchers. Data extracted from the charts included(1) patient demographic information (age, gender, etc), (2)

primary medical diagnosis, (3) date of first home visit, (4)discharge date from home health, (5) wound etiology, size,and depth, (6) duration of wound (expressed in weeks)prior to onset of nursing treatment, (6) wound assessmentcompleted at each visit (wound measurements, tissue de-scription, odor, antibiotic use, Bates Jensen WoundAssessment Tool score if available, patient teaching done,pressure redistribution devices), (7) number of nursing vis-its by care agency and nursing type, (8) length of time onservice, and (9) condition of the wound on discharge.

After collecting data from 237 charts, it was discoveredthat there were elements missing in some records essentialto making an adequate comparison between the care de-livery models. Analysis of these charts revealed an inade-quate sample size to accommodate the power needed todetermine significant differences. Therefore, a secondphase of data collection was undertaken to compile ade-quate sampling with adequate information needed tocomprise a robust sample. Unfortunately, the sample sizeof the no ET (RN/RPN only) remained very small andcharts frequently lacked serial wound measurements. As aresult, this model could not be adequately representedwithin this study. Because the general nursing agencies didnot store discharged charts onsite and did not have a data-base by which to search for charts by etiology, they werelimited to collecting charts as patients were discharged.Five out of 5 agencies participated in the initial phase ofdata collection, but only 2 agencies participated in the sec-ond phase due to time and staffing restrictions.

Wound OutcomesFor the purposes of this study, health benefits were definedas the difference in healing trajectories and mean time to100% wound closure. Healing trajectories have been indi-cated by the US Food and Drug Administration and the US-based Wound Healing Society as the most stringent criteriato determine the efficacy of a new wound healing agent asachieving 100% wound closure.6 Wound healing followsan exponential course, with the rate of change of woundarea progressively decreasing as the residual wound area ap-proaches total closure. Kaplan-Meier survival methodologywas used in this study to create dynamic healing trajecto-ries and compare mean time to 100% closure for statisticalsignificance.7 The method has been reported for woundhealing studies and is useful when there are a significantnumber of patients who do not reach the end point underinvestigation (eg, complete healing).8,9 Therefore, woundhealing was quantified based on (1) time required to com-plete wound healing, (2) time required to discharge, and (3)condition at discharge. Conditions at discharge included(1) wound healed (closed), (2) independent in self-care andhealing, (3) patient discharged but wound not healing, (4)wound-related hospital readmission, (5) non–wound-related hospital readmission, (6) patient expired, (7) pa-tient lost to service, and (8) wound healing and patient dis-charged to other nursing agency.

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Economic AnalysisA cost-effectiveness analysis was completed to determinethe incremental differences between nursing visit costsand time to 100% closure of the wound. Current averagefees for service were provided by the CCAC of WaterlooRegion, Ontario, for the 2005 nursing rates. They were$53.00 (CN) for an RN visit and $43.00 (CN) for an RPNvisit. The ET specialty nursing agency provided actualbilling fees; they were $61.09 (CN) for an ET visit and$48.75 (CN) for an AWOS visit. This fee structure was usedto determine the nursing costs of wound treatment in thecost-effectiveness models. These were used as a standardfor economic evaluation for the whole project. The cost ofmedical resources including pressure redistribution de-vices, dressings, and other adjunctive services was notquantified in this analysis.

Decision AnalysisProbabilistic decision analysis, a method to help cliniciansdevelop policies and make decisions on how best to treatindividual patients, was used as the conceptual model foreconomic data analysis. This analysis was selected todemonstrate the relative “best” or most valued outcome ofeach of the care provider groups. Decision analysis soft-ware “TreeAge Professional-Healthcare Module 2007”10 as-sisted in creating the decision trees and running a MonteCarlo simulation.11 Monte Carlo disease simulation esti-mates the effect of variability among patients in both un-derlying disease progression patterns and individualresponsiveness to treatments.11 The output information ispresented in the form of distributions, which was used toestimate mean costs and mean time to healing. These re-sults can be used to compute cost-effectiveness ratios be-tween the 3 provider models (ET/AWOS only, noET/AWOS care, and hybrid). Distributions were fitted tohealing time and cost results for each caring group andsimulated using 10 000 iterations. A 95% confidence in-terval and graphical representation of the results demon-strated the incremental costs and healing benefits.

Budget Impact AnalysisBudget impact analysis (BIA) is an important part of acomprehensive economic assessment of a healthcare tech-nology or program.12 The purpose is to estimate the finan-cial consequences of adoption and diffusion of ahealthcare intervention within a healthcare system giveninevitable resource constraints. In this study, BIA was usedto predict how an increase or a decrease in ET/AWOS in-volvement in a wound case impacted the trajectory ofspending on nurse visits.

■ Statistical Analysis

All calculations and graphing were performed using SPSS8.0 for Windows.13 Kaplan-Meier survival analysis wasused to measure healing trajectories. Trajectories were con-

structed for ulcers that totally healed (100% closure) andthose that did not (�100% closure) over the period of careoffered by each nursing model. The percentage of patientsachieving total healing versus length of treatment time percare provider model was plotted. For each wound type, alog-rank statistic was used to determine mean time to heal-ing and demonstrate statistical differences between heal-ing trajectories for each caring model. Categorical datawere compared using the �2 test and continuous data werecompared using the t test or Mann-Whitney U test.

■ Results

Subjects Four hundred ninety-six charts were audited in the 2phases of the study. If the general visiting nursing agency’scharts was missing data for charts in the hybrid model, theaudit was augmented by access to that client’s chart in theET nursing agency files (each agency uses its own propri-etary documentation system). Further risk adjustment wascompleted on the data for optimal comparison of caringgroups. A total of 360 chronic wounds were evaluated inthis study; 154 were treated using the ET/AWOS modeland 206 treated by the hybrid model. An additional 54acute surgical wounds included 8 treated by the ET/AWOSmodel and 46 treated by the hybrid model. The samplesize for the ET/AWOS acute wound group was too small tomake a direct comparison, so analysis was made by factor-ing the percentage involvement of the ET/AWOS in thetreatment. Missing data and risk adjustment in the surgi-cal wound type left a total of 43 wounds for comparativeintervention analysis.

Patients in the ET/AWOS model were comparable totheir counterparts in the hybrid model with respect to ageand gender, wound size and depth at initial visit, and useof pressure redistribution interventions (Table 1). However,the 2 groups differed on the wound etiology and location.Wounds in the hybrid group were more likely to be dia-betic (55.6% vs 39.6%, P � .029) and located on the toe(32.4% vs 20.1%, P � .010).

■ Chronic Wounds

Pooled analysis of chronic wounds indicated a faster heal-ing response when the ET/AWOS managed the woundexclusively. Kaplan-Meier survival analysis shows a signif-icantly faster and consistent healing trajectory (100% clo-sure) for the ET/AWOS treated wounds when comparedwith the hybrid group managed wounds (Figure 2). Themean time to 100% closure was approximately 99 and 143 days for the RN ET/AWOS and hybrid groups, respec-tively (Table 2, P � .0006). Analysis of the wounds byetiology yielded similar results with the exception ofvenous ulcers (Table 3).

In the hybrid group, the ET/AWOS involvement wascalculated dividing the number of ET/AWOS visits into the

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total number of visits for each patient/wound case. Thepercentages were grouped into categories (high involve-ment: ET/AWOS involved in 75% to 100% of visits; mod-erate involvement: ET/AWOS involved 50% to 74% ofvisits; mild involvement: ET/AWOS involved 25% to 49%of visits, and minimal involvement: ET/AWOS involved in� 24%). Healing trajectories were seen to improve, as therewas more involvement by the ET/AWOS (Figure 3). A 1-way analysis of variance showed a statistically significant

difference in mean time to complete wound closure withhigher levels of ET/AWOS involvement (Table 4, P � .0002).

Figure 4 compares mean nursing costs in the pooledanalysis of chronic wounds. This was calculated by multi-plying the number of nurse visits by CCAC reimbursementprovided for each nursing qualification and summingthem to a total for each wound case. Where there weremultiple wounds on a patient, the total cost was dividedby the number of wounds treated on the patient. The

TABLE 1.

Patient and Chronic Wound Characteristics, By Caring Group

RN ET /AWOS Specialty Nurse Involvement

RN ET/AWOS Collaborating With Characteristic Specialty Service Alone General Nursing Agency P

Age, mean (SD), y 68.55 (15.76) 69.81 (13.99) .426Women, n (%) 60 (39) 97 (46.9) .134Men, n (%) 94 (61) 110 (53.1)Wound type, n (%)

Diabetic foot ulcer 61 (39.6) 115 (55.6) .029Pressure ulcer 30 (19.5) 31 (15)Venous stasis ulcer 33 (21.4) 32 (15.5)Other diabetic ulcer 30 (19.5) 29 (14.0)

Wound location, n (%)Foot 55 (35.7) 68 (32.9) .010Leg 40 (26.0) 34 (16.4)Mid-region (sacrum, ischial tuberosity, coccyx, 23 (14.9) 22 (10.6)

trochanter)Toe 31 (20.1) 67 (32.4)Other 5 (3.2) 16 (7.7)

Wound size (area � length � width)�4 cm2 112 (74.2) 143 (69.8) .7874 to �16 cm2 34 (22.5) 52 (25.4)16.1 to �36 cm2 2 (1.3) 6 (2.9)36.1 to �80 cm2 2 (1.3) 2 (1.0)�80 cm2 1 (0.7) 2 (1.0)

Wound depthNonblanchable erythema on intact skin 12 (7.9) 10 (5.0) .575Partial-thickness skin loss involving epidermis 58 (38.2) 68 (33.8)

and/or dermisFull-thickness skin loss involving damage or 61 (40.1) 86 (42.8)

necrosis of subcutaneous tissue; may extend down to but not through underlying fascia; and/or mixed partial- and full-thickness and/or tissue layers obscured by granulation tissue

Obscured by necrosis 16 (10.5) 28 (13.9)Full-thickness skin loss with extensive destruction, 5 (3.3) 9 (4.5)

tissue necrosis or damage to muscle, bone, or supporting structures

Pressure relief, %Orthotic use for diabetic foot ulcers 43.1 40.7 .768Pressure redistribution for pressure ulcers 73.3 69.0 .711Compression bandaging for venous ulcers 86.7 78.6 .415

Abbreviations: AWOS, advanced ostomy and wound skills; ET, enterostomal; RN, registered nurse; SD, standard deviations.

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FIGURE 2. Kaplan-Meier time to 100% closure (chronic wounds).

TABLE 2.

Mean Time to 100% Closure of Pooled Chronic Wounds, by Caring Group

Significance (Log-RankMean (SE) Time to 95% Confidence Statistic for Equality

Intervention Sample Size 100% Closure, d Interval of Distributions)

RN ET/AWOS 154 98.58 (9.17) (80.60, 116.56 ) .0006Hybrid 206 143.39 (13.20) (117.51, 169.26)

TABLE 3.

Subgroup Results, Mean Time to 100% Closure, By Wound Type and Caring Group

Sample Mean (SE) Time to 95% ConfidenceSignificance

Intervention Wound Type Size 100% Closure, d Interval Heal Size Depth

RN ET/AWOS Diabetic foot 61 104.74 (13.80) (77.69, 131.79) .017 .753 .774Hybrid 115 149.76 (17.02) (116.40, 183.12 )RN ET/AWOS Pressure ulcers 33 77.78 (12.80) (52.71, 102.86) .014 .405 .144Hybrid 32 186.29 (37.05) (113.67, 258.91)RN ET/AWOS Venous stasis ulcers 30 141.76 (26.43) (89.95, 193.57 ) .303 .712 .742Hybrid 29 103.73 (19.49) (65.53, 141.94 )RN ET/AWOS Other diabetic wound types 30 47.97 (7.94) (32.42, 63.53 ) .008 .429 .197Hybrid 30 105.18 (19.47) (67.02, 143.34 )

Abbreviations: AWOS, advanced ostomy and wound skills; ET, enterostomal; RN, registered nurse; SE, standard error.

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FIGURE 3. Kaplan-Meier time to 100% closure (RN ET/AWOS specialty nurse involvement,chronic wounds).

TABLE 4.

Mean Time to 100% Closure of Chronic Wounds, by Caring Group and RN ET/AWOS Involvement

Mean (SE) Time to 95% ConfidenceInvolvement Sample Size 100% Closure, d Interval Significance

High (75%–100%) 163 98.01 (8.87) (80.64, 115.39) .0002Moderate (50%–74%) 13 76.26 (8.79) (59.03, 93.50)Mild (25%–49%) 33 160.96 (39.16) (84.21, 237.70)Minimal (0%–24%) 127 154.01 (15.16) (124.31, 183.72)

Abbreviation: SE, standard error.

primary reason for the provision of nursing visits was relatedto a chronic wound as identified in the patient chart. Themean cost of nursing visits in the hybrid group was signifi-cantly higher than the ET/AWOS (Figure 4, P � .000).

Figure 5 provides a cost analysis between the providermodels based on wound etiology. The same trend was seenin each wound type. Interestingly, there was a higher costof nurse visits in the hybrid group for the treatment of ve-nous ulcers, although the time to healing, as previouslymentioned, was faster. Figure 6 displays the differences innursing costs as the ET/AWOS becomes more involved inthe case.

Economic Analyses A cost-effectiveness analysis was performed to determinethe cost to achieve complete closure among subjects withchronic wounds. Costs were calculated using 2005 con-tract levels. Probabilistic decision analysis and Monte

Carlo simulation were used to estimate the expected costsand time to complete closure of chronic wounds treatedby the ET/AWOS alone or hybrid care models. The nursingcosts and healing times assumed a normal distribution. Theresults indicate that the ET/AWOS model can expect to pro-vide a patient with approximately 45 more ulcer-free daysat an expected cost savings of $5927.00 (CN) per woundcompared to the hybrid care model (Table 5). Analysis alsorevealed that the greater the ET/AWOS involvement inwound management, the greater the response to healingand the lower the cost (Table 5). With minimal ET/AWOSinvolvement, the cost was approximately $10 376.00 (CN)per chronic wound as compared a cost of $1330.00 (CN) perwound with high ET/AWOS involvement. Expected time tocomplete closure was 97 days compared to 158 days. Theseresults indicate that the ET/AWOS only care model wasmore cost-effective in healing wounds to complete closurewhen compared to the hybrid care model.

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Figure 7 shows the results of analysis of the meandifference in nursing visit cost and healing time. Themajority of point estimates fall in the northeast and south-east quadrants of the cost-effectiveness plane, suggestingthat the hybrid care model is associated with a longer timeto achieve complete closure of chronic wounds. A major-ity of the point estimates in those quadrants lie in thenortheast plane where the nursing visit cost is higher forthe hybrid model than the ET/AWOS only model.

■ Acute Wounds

Acute wounds treated by visiting nurses tended to besurgical wounds and were associated with few, if any, com-plications. However, in this study, only acute wounds thatmet the indicators for an ET consultation (stalled healingdue to intrinsic or extrinsic factors) were included.14 For astatistical comparison, acute wounds were categorized intoET/AWOS involvement �50% and those with �50%ET/AWOS involvement. Patients in ET/AWOS care modeldid not differ from those managed by the hybrid caremodel with respect to age, gender, wound size and depthat initial visit, or location (Table 6).

Kaplan-Meier survival analysis revealed a faster andmore consistent healing trajectory when the ET/AWOS

FIGURE 4. Mean cost of nursing visits per chronic wound, bycaring group.

FIGURE 5. Mean cost of nursing visits for each chronic wound,by caring group and wound type.

FIGURE 6. Mean cost of nursing visits per chronic wound, by RN ET/AWOS involvement intreatment.

TABLE 5.

Cost-Effectiveness Results (Chronic Wounds), Monte Carlo Simulation

Mean (SD) Incremental Incremental Effectiveness Time Effectiveness Time Cost-

Caring Group Mean (SD) Cost Cost to 100% Closure, d to 100% Closure, d Effectiveness Ratio

RN ET/AWOS $1 183.00 ($2 513.00) 98.33 (112.75) $12.00Hybrid $7 110.00 ($18 560.00) $5 927.00 143.71 (187.74) 45.38 $49.00High involvement $1 330.00 ($3 669.00) 96.56 (113.52) $14.00Moderate involvement $1 540.00 ($1 371.00) $210.00 76.47 (31.69) �20.09 $20.00Mild involvement $7 795.00 ($29 800.00) $6 255.00 157.82 (226.20) 81.35 $49.00Minimal involvement $10 376.00 ($20 540.00) $2 581.00 157.16 (171.35) �0.66 $67.00

Abbreviation: SD, standard deviations.

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was more involved in treatment (Figure 8). The mean timeto 100% closure was approximately 86 days when theET/AWOS participated more than 50% of the time as com-pared to 165 days when they participated in less than 50%of visits (Table 7, P � .0704). Statistically, the healingtrajectories were equivalent, possibly owing to the smallsample size and wide variability in healing times.

Economic Analyses Figure 9 compares mean nursing costs in the ET/AWOS in-tervention analysis for acute wounds. Costs were calcu-

lated by multiplying the number of nurse visits by CCACreimbursement provided for each nursing qualificationand summing them to a total for each wound case. Wherethere were multiple wounds on a patient, we divided thetotal cost by the number of wounds treated on the patient.The mean cost of nursing visits when the ET/AWOS wereinvolved in more than 50% of visits was $1462.50 (CN)per wound treated as compared to $4366.45 (CN) whenthe ET/AWOS was involved in less than 50% of visits.

Probabilistic decision analysis and Monte Carlo simu-lation were used to estimate the expected costs and timeto complete closure of acute wounds referred to theET/AWOS for consultation. Results indicate that a greaterthan 50% involvement by the ET/AWOS can be expectedto provide a patient with approximately 77 more wound-free days at an expected cost savings of $9591.00 (CN) perwound when compared to a model of ET/AWOS involve-ment in less than 50% of visits (Table 8).

Figure 10 displays the mean difference in nursing visitcost and healing time for acute wounds referred to theET/AWOS model. The majority of point estimates fall inthe southwest quadrant of the cost-effectiveness plane,suggesting that the ET/AWOS involvement in more than50% of visits is associated with a shorter time wound clo-sure and a lower cost than involvement by the ET/AWOSin less than half of visits.

Budget Impact AnalysisStatistics were acquired from the CCAC of Waterloo regionregarding the number of wound patients serviced from

FIGURE 7. Incremental cost-effectiveness plane of using thehybrid model for the healing of chronic wounds.

TABLE 6.

Patient and Acute Wound Characteristics, by RN ET/AWOS Involvement

RN ET /AWOS Specialty RN ET /AWOS SpecialtyService Involvement Service Involvement

Characteristic (0%–50% Involvement) (51%–100% Involvement) P

Age, mean (SD), y 51.25 (19.85) 53.93 (30.80) .740Women, n (%) 14 (48) 8 (57) .586Men, n (%) 15 (52) 6 (43)Wound size (area � length � width ), n (%)

�4 cm2 12 (41.4) 4 (28.6) .4654 to �16 cm2 13 (44.8) 6 (42.9)16.1 to �36 cm2 4 (13.8) 4 (28.6)

Wound depth, n (%)Nonblanchable erythema on intact skin 0 (0.0) 0 (0.0) .473Partial-thickness skin loss involving epidermis and/or dermis 2 (7.2) 0 (0.0)Full-thickness skin loss involving damage or necrosis of 23 (88.5) 11 (84.6)

subcutaneous tissue; may extend down to but not through underlying fascia; and/or mixed partial- and full-thickness and/or tissue layers obscured by granulation tissue

Obscured by necrosis 1 (3.8) 2 (15.4)Full-thickness skin loss with extensive destruction, tissue 0 (0.0) 0 (0.0)

necrosis or damage to muscle, bone, or supporting structures


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May 1, 2006, to March 31, 2007. Using these statistics, aset of prevalence statistics were interpolated representingthe number of wounds encountered in the Province ofOntario over a 1-year period. Using a rate of 2.0 per 1000patients and assuming a chronic wound lasts 4 months,we estimated about 45,000 venous stasis ulcer patients in1 year. Diabetic foot ulcer prevalence is equivalentaccording to the rate per 1000 patients of venous stasisulcers. Pressure ulcer prevalence estimates were increased40% over venous stasis estimates (63,000), and otherdiabetic wounds were estimated as slightly higher thandiabetic foot ulcers (50,000). Surgical wounds wereestimated to occur more frequently than chronic wounds.

The number of acute wound patients were increased by400%, reflecting the relative prevalence from regional toprovincial estimates (200,000). Approximately 70% of thechronic wounds would qualify for ET/AWOS consultationbased on the indicators for ET consultation from theCCAC Waterloo. We then estimated the total budget im-pact to the Ministry of Health in the Province of Ontarioby ET/AWOS involvement in acute and chronic woundmanagement (Table 9). The predicted savings to theMinistry of Health is approximately $1.3 billion (CN) peryear for chronic wounds and $575 million (CN) per yearfor acute wounds when the involvement of the ET/AWOSnurse is more than 50%.

FIGURE 8. Kaplan-Meier time to 100% closure (RN ET/AWOS specialty nurse involvement,acute wounds).

TABLE 7.

Mean Time to 100% Closure of Acute Wounds, by RN ET/AWOS Involvement

Significance Mean (SE) (Log-Rank Statistic

Time to 100% 95% Confidence for Equality of Intervention Sample Size Closure, d Interval Distributions)

RN ET/AWOS (0%–50% 29 164.82 (28.45) (109.06, 220.57) .0704involvement)

RN ET/AWOS (51%–100% 14 86.04 (17.66) (51.43, 120.65)involvement)

Abbreviations: AWOS, advanced ostomy and wound skills; ET, enterostomal; RN, registered nurse.

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■ Discussion

Our findings support 3 major conclusions: (1) theET/AWOS only care model provides more rapid woundhealing times than a hybrid model that combinesET/AWOS with RN/RPN; (2) the ET/AWOS only model ismore cost-effective than the hybrid model; and (3) withinthe hybrid model, cost and wound healing outcomes wereimproved when ET/AWOS saw the patient on 50% of vis-its or more frequently. These findings were achieved, eventhough the wounds treated by the ET/AWOS care modelwere larger in size than wounds treated by the RN/RPN (noET/AWOS) model, supporting the assumption that spe-cialized knowledge and clinical expertise are beneficialwhen managing larger and more complex wounds.

In 1994, Arnold and Weir15 compared wound healingoutcomes achieved by non-ET nurses and ET nurses in thesame setting. They demonstrated that ET/WOC nurses de-livering evidence-based wound care improved the healingrate by 100% (36.3% non-ET vs 78.5% ET nurses) withinthe same time frame. This study included 344 woundscared for by ET/AWOC nurses and 464 wounds cared forby staff nurses. However, this study did not include a hy-brid model of ET/AWOC and staff nurses working collab-oratively. Nevertheless, we believe that the hybrid modelwe describe is relevant because it most closely reflects re-ality in community nursing settings, where the ET nurseserves as the wound care expert, assessing and applyingevidence-based interventions.

White16 described the activity of avoiding delayedhealing as one of optimizing healing. This begins with adetailed and regular assessment, using a validated and re-liable wound assessment tool, and planning and deliver-ing treatment that is evidence based. Standards of care forwound healing include principles of wound bed prepara-tion, maintenance of a moist wound healing environ-ment, use of compression for venous ulcers, or pressureredistribution for diabetic foot ulcers or venous ulcers. TheET specialty agency involved in this study used measuresdescribed by DiCenso and Cullum17 to provide clinical ex-pertise and knowledge of current clinical evidence to de-liver care that led to enhanced wound healing rates in acost-effective manner.

Venous healing rates were higher in the hybrid caremodel when compared to the ET/AWOS only model.There are 2 possible explanations for this outcome. Onepatient with many years’ history of recurrent venous ul-cerations in the ET/AWOS group was nonadherent withhigh-compression therapy and had an extended length ofstay. This patient should have been transferred to the gen-eral nursing agency for care and was not. While this typeof case would be excluded in a prospective trial, it repre-sents the “real-world” cases captured in a retrospectiveanalysis. All patients with venous leg ulcers, whether purevenous or mixed arterial/venous etiology, are assessed forcompression therapy by the ET nurse who either each car-ries a Doppler to perform Ankle Brachial Indexes or sug-gests more definitive studies for clients who have the riskof calcified vessels or who have signs of arterial disease.Compression safe for the client’s vasculature is initiated aspart of the plan of care, which means that all clientswhether in the hybrid or the RN ET/AWOS group wouldbe receiving appropriate therapy. It may also be thattighter inclusion/exclusion criteria for an audit of venousetiology ulcers, stipulating that clients be adherent to theplan of care, or that ulcers be of less than a certain agewould produce different results in the audit.

■ Strengths

This is the first ever cost-effectiveness study of ET/AWOSnursing practice. There are no preexisting comparable

TABLE 8.

Cost-Effectiveness Results (Acute Wounds), Monte Carlo Simulation

IncrementalEffectiveness Cost-

Incremental Mean (SD) Effectiveness Time to 100% EffectivenessCaring Group Mean (SD) Cost Cost Time to 100% Closure, d Closure, d Ratio

RN ET/AWOS $2 249.00 ($2 955.00) 85.94 (73.61) $26.00(51%–100%)

RN ET/AWOS $11 840.00 ($18 011.00) $9 591.00 163.26 (153.50) 77.32 $73.00(0%–50%)


FIGURE 9. Mean cost of nursing visits per acute wound, by RNET/AWOS involvement in treatment.

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data, and as such this study will be subject to muchscrutiny. It can serve as a model for further study andanalysis not only within this specialty but also for othernursing specialties. In addition, this model can provide atemplate for further study for other models of ET/AWOSpractice.

The results supported what the specialty agency be-lieved to be true about the uniqueness of the models of

care delivery based on their observations. The more fre-quently the ET/AWOS nurse visited the patient, the morepositive were the healing outcomes and the cost savings innursing time. It also demonstrates successful collaborationamong different representations of healthcare delivery.The CAET is a professional nursing association represent-ing and fostering the development of its ET nursing mem-bers by utilizing research and theory; reflective practiceand experience in the ETNEP; offering continuing educa-tional support; and the recognition as a nursing specialtywithin the Canadian Nurses Association for its members.These qualities are illustrated in Harrison’s Evidence forPractice Framework.18,19

■ Limitations

It was not possible to meet the aim of a minimum of20 charts per care provider group for each type of wound,with a total of 140 patients for each care provider group(all wounds). This was directly influenced by the fact thatthe visiting nursing agencies did not store their dischargedcharts on site and did not have a computerized databaseto list charts by wound etiology. The RN/RPN only (noET/AWOS) model did not yield enough cases for analysis,partly because many nurses did not record serial woundmeasurements.

The small cross-section of practice within 2 locales inOntario may not be representative of all practice sites. Theunique ET/AWOS nurse delivery model lacks a comparator

FIGURE 10. Incremental cost-effectiveness plane of RN ET/AWOSspecialty nurse involvement for the healing of acute wounds.

TABLE 9.

Predicted Financial Impact on the Ontario Ministry of Health and Long-Term Care Budgets for RN ET/AWOSInvolvement in Community Wound Management

RN ET/AWOS Involvement (Chronic Wounds)

High Moderate Mild Minimal

Expected cost per $1 330.00 $1 540.00 $7 795.00 $10 376.00wound treatment

Chronic ulcer 203 000 203 000 203 000 203 000prevalence (1 y)a

Estimated number 142 100 142 100 142 100 142 100 of patients qualifying for referral (70%)

Total yearly cost $188 993 000.00 $218 834 000.00 $1 107 669 500.00 $1 474 429 600.00(predicted)

RN ET/AWOS Involvement (Acute Wounds)

�50% Involvement �50% Involvement

Expected cost per wound treatment $11 840.00 $2 249.00Acute wound prevalence (1 y)a 200 000 200 000 Estimated number of patients qualifying for referral (30%) 60 000 60 000Total yearly cost (predicted) $710 400 000.00 $134 940 000.00

aAssume 1 wound per patient.Abbreviations: AWOS, advanced ostomy and wound skills; ET, enterostomal; RN, registered nurse.

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elsewhere in country, but provided ease of access to a largenumber of charts of clients who had received this model ofcare. To generalize to other settings may be limited byvirtue of constraints within regional healthcare systems.

■ Implications for Clinical Practice

The results of this study support a paradigm shift(Figure 11) to redirect some of the costs of existing gen-eral nursing to an increased budget for ET/AWOS nurses,who are qualified nursing wound specialists, performingcomprehensive baseline and monitored assessments,comprehensive and interprofessional development oftreatment plan, consultative in complex wounds, appli-cation and dissemination of wound research, and devel-opment. They demonstrate both clinical practice andeconomical advantages on significant patient care out-comes. The greater the knowledge and skills of the nurse,the better the patient outcomes (cost outcomes, debride-ment, documentation of teaching, and use of advancedwound care dressings). This allows for cost savings andother resources to be redirected into other valuablehealthcare delivery issues, that is, more staffing, staffingeducation, product, and research. Indirect involvementof the ET nurse may influence practice of others throughmentoring, as seen with the ET/AWOS model of the spe-cialty agency. This agency is led by ET nurses who pro-vide both direct and indirect management of wounds forall of their patients. Fifty percent of visits are made by RNETs and 50% by RN AWOS who are educated and skillprepared by ET nurses with ongoing supervision and con-sultation by the ETs. At no point does the RN with AWOStreat a patient from admission to discharge indepen-dently. Indirect impact by the ET nurse can also includeeducation, program development and management,policies and procedures, care paths, assessment, docu-mentation and teaching tools, product selection, partici-pation in wound research, and development best practiceguidelines.

Our results suggest that limiting the number of ET vis-its per patient may result in less positive patient outcomesfor patients with acute and chronic wounds. In contrast,an increased frequency of visits and consistent presence ofan ET/AWOS nurse will better support the accountabilitiesof nursing agencies when managing patients withwounds.

■ Conclusions

ET/AWOS nurses positively impact healing trajectoriesand cost outcomes of chronic and acute wounds as directcare providers and when practicing in a hybrid model thatcombines ET/AWOS care with care delivered by RN/RPN.These specialty practice nurses deliver skilled care to pa-tients with complex wounds, and the results of this studyprovide further evidence that ET/AWOS nurses are essen-tial leaders on the wound care team.

■ ACKNOWLEDGMENTS

The authors acknowledge and thank the CanadianAssociation for Enterostomal Therapy for their collabora-tion and funding of this study. They also acknowledgeLauren Alexander and Cathy O’Brien, McMasterUniversity Conestogo College BScN program; Lisa Parks,Julie Straus, and Jodie Perkins, ET NOW; Kim Voelker andPam Hurrell, CCACWW; Tally Hill ParaMed, SueWideman, and Deb Dalton, CarePartners; Deb Kauk, LaniMavin, and Kelly Baechler, Comcare in Waterloo Region;Anita Coles, Oxford CCAC; Cathy Walker, CarePartnersOxford County; Dr Steven Abdool, Homewood HealthCentre Research Ethics Board; and Dr R. Gary Sibbald andDr Douglas Queen, Provincial Outcomes Project. The au-thors are appreciative of the valued editorial assistancefrom Kathryn Kozell, MScN, RN, ACNP, ET, President ofthe CAET.

■ References 1. Knight L. Personal discussion re: visit volume and characteris-

tics for Care Partners visiting nursing agencies in the provinceof Ontario. 2004.

2. Heater BS, Becker AM, Olson RK. Nursing interventions and pa-tient outcomes: a meta-analysis of studies. Nurs Res. 1988;37(5):303–307.

3. Waterloo Region Community Care Access Centre. CCAC090Enterostomal Therapy (ET) Consultation Request form Mar3/05.

4. Orridge C, Purbhoo D. Wound Care: A Guiding Framework: AJoint CCAC Initiative in Collaboration With Their Service Partners.Toronto, Ontario: Wound Review Project, Toronto CCAC;2004.

5. Expectations of Registered Nurses and Registered PracticalNurses. The College of Nurses of Ontario Web site. http://www.cno.org/international_en/intro/expectations.htm. AccessedDecember 18, 2007.

6. Robson MC, Maggi SP, Smith PD, et al. Ease of wound closureas an endpoint of treatment efficacy. Wound Repair Regen.1999;7(2):90–96.FIGURE 11. Paradigm shift with respect to ET practice.

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7. Kaplan E, Meier P. Nonparametric estimation from incompleteobservation. J Am Stat Assoc. 1958;53:457–481.

8. Polansky M, van Rijswijk L. Utilizing survival analysistechniques in chronic wound healing studies. Wounds. 1994;6:150–158.

9. Peto R, Pike C, Armitage P, et al. Design and analysis of ran-domized clinical trials requiring prolonged observation of eachpatient; part II: analysis and examples. Br J Cancer.1977;35:1–39.

10. TreeAge Software, Inc. http://www.treeage.com.11. Richter A, Mauskopf J. Monte Carlo simulation in health care

models. Value Health. 1998;1(1):84–85.12. Mauskopf JA, Sullivan SD, Annemans L, et al. Principles of

good practice for budget impact analysis: report of the ISPORtask force on good research practices—budget impact analysis.Value Health. 2007;10(5):336–347.

13. SPSS, Inc. http://SPSS.com.

14. Sussman C, Bates-Jensen B. Assessment of the skin andwound. In: Wound Care a Collaborative Practice Manual. 3rd ed.Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins;2007:106.

15. Arnold N, Weir D. Retrospective analysis of healing in woundscared for by ET nurses versus staff nurses in a home setting. JWound Ostomy Contin Nurses. 1994;21(4):156–160.

16. White R. Delayed wound healing: who, what, when and why?Nurs Stand Suppl. 2006:47–54.

17. Dicenso A, Cullum N, Ciliska D. Implementing evidence-basednursing: Some misconceptions. Evidence-Based Nursing. 1998, 1April:38–40.

18. Harrison MB. Queen’s Nursing 301 Course, ProfessionalPractice Framework.

19. Harrison MB. Paper presented at: Evidence Based Nursing:Theory Science and Practice Workshop; December 2003;Queen’s University, Kingston, Ontario, Canada.

Call for Authors: Wound Care

• Review articles, case studies, case series, and original research reports focusing on the potential role of unprocessedhoney in wound healing

• Review articles or original research reports focusing on the antibacterial properties of silver• Continuous Quality Improvement projects, research reports, or institutional case studies focusing on innovative

approaches to reduce facility-acquired pressure ulcers• Case studies, case series, review articles, and original research reports focusing on topical therapies for pressure

ulcers, vascular ulcers, or neuropathic (diabetic foot) ulcers• Original research reports focusing on the histologic and clinical effects of negative pressure wound therapy

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