Faculdade de Medicina da Universidade do Porto

Risk factors which influence the evolution of acute pain into

chronic pain

Systematic Review Turma 6

Introduction

Definitions

Context

Objective

PainPain

Unpleasant sensory and emotional experience associated with actual or potential tissue damage [1].

Acute PainAcute Pain

Pain connected with real tissue lesions [1]; Shorter duration; Needs a treatment model

Chronic painChronic pain

Pain without biological value that has persisted beyond normal tissue healing time (3 months) [1].

“Current continuous or intermittent pain or discomfort which as persisted for more than three months, with recent or frequent seeking of treatment

or use of analgesic medication” [3].

Chronic painChronic pain

Opposite to acute pain, needs a rehabilitative rather than a treatment model [2].

Among the most disabling and costing afflictions in North America, Europe and Australia [4]..

Must be understood in a multi-dimensional way [2]. More women than man are affected Prevalence increases with age It is estimated that between 10 and 15 % of the population

suffers from it [2].

Chronic painChronic pain

Chronic no-malignant pain is commonest at limbs and joints, Chronic no-malignant pain is commonest at limbs and joints, at the back, as well as at neck and head [6][7].at the back, as well as at neck and head [6][7].

Has a deep impact on suffers, as it prorogues a sense of loss of Has a deep impact on suffers, as it prorogues a sense of loss of their lives, due to loss of confidence and self-esteem their lives, due to loss of confidence and self-esteem associated with psychological, social and economical associated with psychological, social and economical

implications [2].implications [2]. To manage it, to issues must be take in count [2]:To manage it, to issues must be take in count [2]:

- treatment - - treatment - drug therapy, invasive therapy, alternative drug therapy, invasive therapy, alternative therapiestherapies

- rehabilitation - - rehabilitation - physiotherapyphysiotherapy

ContextContext

Acute and chronic pain are intimately correlatedAcute and chronic pain are intimately correlated

Many factors are in the origin of such transitionMany factors are in the origin of such transition::- individual factors (obesity, severe radiating pain…)- individual factors (obesity, severe radiating pain…)

- psychological factors (anxiety, severe depression…)- psychological factors (anxiety, severe depression…)

- workplace factors (heavy jobs, monetary compensation - workplace factors (heavy jobs, monetary compensation during inability…)during inability…)

- …- …

ContextContext

Chronic pain may lead to loss of employment, loss of social Chronic pain may lead to loss of employment, loss of social and home roles, sleep disorders, having much psychological, and home roles, sleep disorders, having much psychological, social and economic implications [2]social and economic implications [2]

Importance and relevance of our work

ObjectiveObjective

To review systematically the literature regarding risk factors which influence the evolution of acute pain into chronic pain

Systematic ReviewSystematic Review

The key steps are [9]:The key steps are [9]: Formulation of a focused review questionFormulation of a focused review question A comprehensive, exhaustive search and inclusion of A comprehensive, exhaustive search and inclusion of

primary studiesprimary studies Quality assessment of included studies and data Quality assessment of included studies and data

extractionextraction Synthesis of study resultsSynthesis of study results Interpretation of the results and report-writingInterpretation of the results and report-writing

Formulation of the QuestionFormulation of the Question

It was verified that studies had already been made about the It was verified that studies had already been made about the subject in interestsubject in interest

Our target population is the published articles indexed on Our target population is the published articles indexed on MedlineMedline

Participants are articles that refer to the evolution of acute pain Participants are articles that refer to the evolution of acute pain into chronic paininto chronic pain

Cohort Studies were selected as the indicated Type of Study. No Cohort Studies were selected as the indicated Type of Study. No intervention will be appliedintervention will be applied

The pretend result is the achievement of a relation between the The pretend result is the achievement of a relation between the existence of certain factors (risk factors) and the development existence of certain factors (risk factors) and the development of chronic pain in individuals previously suffering of acute of chronic pain in individuals previously suffering of acute painpain

Formulation of the QuestionFormulation of the Question

Systematic Review of pre-existing literature Systematic Review of pre-existing literature indexed on Medline, that refers and is based indexed on Medline, that refers and is based on cohort studies, in order to analyse and on cohort studies, in order to analyse and evaluate the relation between the presence of evaluate the relation between the presence of certain risk factors and the evolution of an certain risk factors and the evolution of an acute pain into a chronic painacute pain into a chronic pain

Research and Study SelectionResearch and Study Selection

Bibliographic ResearchBibliographic Research

Study SelectionStudy Selection

Bibliographic ResearchBibliographic Research Bibliographic Database: MedlineBibliographic Database: Medline

Established Limits: HumansEstablished Limits: Humans

Separated sensitive research Queries:Separated sensitive research Queries:““Chronic”, “Pain”, “Chronicity”Chronic”, “Pain”, “Chronicity”

Application of Boolean operators:Application of Boolean operators: ““Chronicity AND Pain”, “Chronic AND Pain”, “Chronicity AND Chronicity AND Pain”, “Chronic AND Pain”, “Chronicity AND

Pain AND Factors”, “Chronicity AND Pain AND Factors AND Cohort Pain AND Factors”, “Chronicity AND Pain AND Factors AND Cohort Studies”, “(“Chronicity AND Pain”) OR (“Chronic AND Pain”)”Studies”, “(“Chronicity AND Pain”) OR (“Chronic AND Pain”)”

Bibliographic ResearchBibliographic Research

Selection of adequate Query:Selection of adequate Query:

““Chronicity AND Pain”Chronicity AND Pain”

Participants: 369 articlesParticipants: 369 articles

Study SelectionStudy Selection

Definition of Selection Criteria:Definition of Selection Criteria:

Exclusion CriteriaExclusion Criteria

Inclusion CriteriaInclusion Criteria

Study SelectionStudy Selection

Exclusion Criteria:Exclusion Criteria:

Studies that do not consider that acute pain Studies that do not consider that acute pain becomes chronic pain in a period of three becomes chronic pain in a period of three monthsmonths

Articles that do not include cohort studiesArticles that do not include cohort studies

Study SelectionStudy Selection

Inclusion Criteria:Inclusion Criteria:

Cohort Studies that refer to factors wich Cohort Studies that refer to factors wich influence the evolution of acute pain into influence the evolution of acute pain into chronic painchronic pain

Studies that include certain types of painStudies that include certain types of pain Studies that refer to certain types of factorsStudies that refer to certain types of factors

Study SelectionStudy Selection

Organization of reviewer groups:Organization of reviewer groups:

4 Reviewer Groups: three groups of 2 4 Reviewer Groups: three groups of 2 elements and one group of 3 elementselements and one group of 3 elements

4 Article Groups: three of 92 articles and one 4 Article Groups: three of 92 articles and one of 93 articlesof 93 articles

Study SelectionStudy Selection

Articles Revision by Titles and AbstractsArticles Revision by Titles and Abstracts Application of Exclusion CriteriaApplication of Exclusion Criteria

““Cohort Studies”: X articles excludedCohort Studies”: X articles excluded

““Chronic Pain Definition”: Y articles excludedChronic Pain Definition”: Y articles excluded Articles excluded by language different from Articles excluded by language different from

English: Z Articles excludedEnglish: Z Articles excluded

Study SelectionStudy Selection

Remaining Articles Revision by Full TextRemaining Articles Revision by Full Text Exclusion of articles which full text is not Exclusion of articles which full text is not

available: S articles excludedavailable: S articles excluded Application of exclusion criteria: Q articles Application of exclusion criteria: Q articles

excludedexcluded Application of inclusion criteriaApplication of inclusion criteria

Study SelectionStudy Selection

Reference Management software:Reference Management software: Register causes of exclusionRegister causes of exclusion List of articles included in the systematic List of articles included in the systematic

review: W articlesreview: W articles

Quality AssessmentQuality Assessment

Organization of reviewer groupsOrganization of reviewer groups

Quality criteriaQuality criteria

Quality AssessmentQuality Assessment

Quality criteria:Quality criteria: The sample of patients is representative and The sample of patients is representative and

homogeneoushomogeneous Patients are homogeneous with respect to prognostic Patients are homogeneous with respect to prognostic

risk, exposure to factorsrisk, exposure to factors The follow up is sufficiently completeThe follow up is sufficiently complete Measurements of the outcomes are made in the same Measurements of the outcomes are made in the same

way on both groups (exposed and unexposed)way on both groups (exposed and unexposed)

Quality AssessmentQuality Assessment

Exclusion of articles that lack quality, not being Exclusion of articles that lack quality, not being compatible with the quality criteria establishedcompatible with the quality criteria established

Stratification of studies by qualityStratification of studies by quality

Data ExtractionData Extraction

Organization of reviewer groups for extraction Organization of reviewer groups for extraction of dataof data

Data extractionData extraction

Processing the data on appropriate softwareProcessing the data on appropriate software

Data ExtractionData Extraction

Data extraction on:Data extraction on: Information about existing influential factors:Information about existing influential factors:

Which factors;Which factors;How many factors was each individual exposed to;How many factors was each individual exposed to;How long was each individual exposed to these factors How long was each individual exposed to these factors

before developing acute pain and after developing acute painbefore developing acute pain and after developing acute pain Information on measurements taken after the development of Information on measurements taken after the development of

acute painacute pain Information on type of painInformation on type of pain Information on period of pain existenceInformation on period of pain existence

Study ResultsStudy Results

Analysis of DataAnalysis of Data

Synthesis and Summary of study Results:Synthesis and Summary of study Results: Tabulation of study characteristicsTabulation of study characteristics

ResultsResults PublishingPublishing

Results published in a Scientific Article:Results published in a Scientific Article:IntroductionIntroductionObjectiveObjectivePopulation studied and MethodsPopulation studied and MethodsResultsResultsDiscussion/ConclusionDiscussion/Conclusion

ReferencesReferences[1] [1] http://http://www.iasp-pain.orgwww.iasp-pain.org; IASP – International Association for the Study of Pain; IASP – International Association for the Study of Pain[2] Smith BH; Hopton JL and Chambers WA; [2] Smith BH; Hopton JL and Chambers WA; Chronic pain in primary care; Family PracticeChronic pain in primary care; Family Practice ; ;

1999; 16; 475-482 1999; 16; 475-482 [3] Purves AM, Penny K, Munro C [3] Purves AM, Penny K, Munro C et al.et al. Defining chronic pain for epidemiological research – Defining chronic pain for epidemiological research –

acessing a subjective definition. acessing a subjective definition. The Pain Clinic The Pain Clinic 1998; 10; 139-147.1998; 10; 139-147.[4] IASP – Pain Clinical Updates; volume XI, No. 2; June 2003[4] IASP – Pain Clinical Updates; volume XI, No. 2; June 2003[5] Von Korff M, Dworkin SF, Le Resche L. Graded chronic pain status: na epidemiologic [5] Von Korff M, Dworkin SF, Le Resche L. Graded chronic pain status: na epidemiologic

evaluation. evaluation. PainPain 1990; 40: 279-291 1990; 40: 279-291[6] Bowsher D, Rigge M, Sopp L. Prevalence of chronic pain in the British population: a [6] Bowsher D, Rigge M, Sopp L. Prevalence of chronic pain in the British population: a

telephone survey of 1037 households. telephone survey of 1037 households. The Pain Clinic The Pain Clinic 1991; 4: 223-2301991; 4: 223-230[7] Brattberg G, Thorslund M, Wilkman A. The prevalence of pain in the general population. The [7] Brattberg G, Thorslund M, Wilkman A. The prevalence of pain in the general population. The

results of a postal survey in a county in Sweden. results of a postal survey in a county in Sweden. PainPain 1989; 37: 215-222 1989; 37: 215-222[8] Fransen M, Woodward M, Norton R [8] Fransen M, Woodward M, Norton R et alet al, Risk Factors Associated with the Tansition From , Risk Factors Associated with the Tansition From

Acute to Chronic Occupational Back Pain, Acute to Chronic Occupational Back Pain, Spine, Spine, volume 27, number 1, pp 92-98, 2002volume 27, number 1, pp 92-98, 2002 [9] Pai M, McCulloch M, Gorman JD [9] Pai M, McCulloch M, Gorman JD et alet al, Systematic reviews, Systematic reviews

and meta-analyses: An illustrated, step-by-step guide. and meta-analyses: An illustrated, step-by-step guide. The nationalThe nationalmedical journal of India,medical journal of India, volume 17, No2, 2004 volume 17, No2, 2004