VTE prevention: Real-world outcome data

VTE prevention: Real-world outcome data

Domenico PaganoConsultant Cardiothoracic Surgeon

Clinical Director Quality & Outcomes Research UnitUniversity Hospital Birmingham, UK

‘VTE PREVENTION NHS SHOWCASE’ 16th September 2013

Quality and Outcomes Research UnitUniversity Hospital Birmingham

Primary Care and Population HealthUniversity College London, UK

Death from PE

80% autopsy rate

9% PE

Clinical diagnosis wrong in 84% of cases

What is the incidence in 2013?

Karwinski & Svendsen J Clin Path 1989

VTE-PE Deaths in Europe

Diagnosed Sudden Undiagnosed0

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Number

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Evidence based medicine1970’s

• Trials post surgical thromboprophylaxis– Heparin, aspirin, dextrans

Power to detect reduction fatal PE 0.8% - 0.4%

20,000

Commissioning for Quality and Innovation (CQUIN) 2010-2011

• AIM: Reduce avoidable death, disability and chronic ill health from venous-thromboembolism (VTE)

• METHOD: >90% of all patients admitted to hospital should have VTE risk assessment

• DRIVER: Up to £ 500,000 withheld from large acute trusts who do not achieve target

CQUIN

VTE risk assessment

Intervention (socks, pharmacological)

Patient pathway: From risk assessment to outcome

Reduced VTE(fatal, non fatal)

Outcome for payment Patient and staff awareness of VTE

Increased non fatal VTE, reduced fatal VTE

Outcome of interest

Aim of our study

• Assess whether achieving the CQUIN target had impact on:– VTE Mortality– VTE non fatal hospital readmissions

Study Population163 hospital trusts; July 2010-March 2012

• Principal analysis:– All hospital admission > 3 days

• Supportive analyses:– Admissions < 4 days– Day cases– Clinical sub-groups

Data source

HES ONS UNIFY2

163 Acute TrustsAdmissions between:July 2010-March 2012

Death certificate data Hospital levelVTE-assessment data

Rate of VTE assessment in England

Monthly assessment rate by trust

Summary DataJuly 2010- March 2012

VTE Risk Assessment 17,528.316 80.60%Admissions > 3 days 4,141,041 23.62%VTE-Related Readmissions 8,578 0.21%VTE In-Hospital deaths 4,334 0.10%VTE In-Hospital deaths ( Primary) 1,318 0.03%VTE deaths within 90 days 1,651 0.04%VTE deaths within 90 days (Primary) 895 0.02%

In-Hospital Deaths

Post-discharge Deaths

Primary VTE deaths over time

Statistical Analyses• Non linear mixed models

– Poisson / Mixed error– Log Link Function– Radial Smoother Spline function for time (random effects)– Random Intercepts (Trusts)– Including count of events of interest by trust / month as response

variable– Offset is loge(n) where n is the number of relevant admissions– Fixed effect time is centred scale for month (across 21 months

included)– Fixed effect is whether the trust has achieved quality standards in

the relevant month (binary)

Enabling estimation of the change in risk associated with achieving screening target

End-point definitions

• Primary VTE Death: VTE in Position 1 death certificate

• VTE Related Death: VTE position 1-3 death certificate

• In-Hospital and 90 days post-discharge• Total: in-hospital + 90 days post-discharge• Non-Fatal Readmissions

* VTE ICD-10 codes from the NHS-Outcome Framework 2013/14

Patients >3 days hospital stay

0.5 1 2

Total Primary VTE related deaths 0.85 (0.75, 0.96; p=0.011: n=2213)

Total VTE related deaths 0.92 (0.85, 0.99; p=0.033: n=5985)

Primary VTE related inhospital deaths 0.86 (0.74, 1.01; p=0.061: n=1318)

VTE related inhospital deaths 0.92 (0.84, 1.00; p=0.057: n=4334)

Primary VTE Deaths at 90 days 0.81 (0.67, 0.97; p=0.026: n=895)

VTE related deaths at 90 days 0.91 (0.79, 1.05; p=0.196: n=1651)

VTE related Readmissions 1.04 (0.97, 1.11; p=0.301: n=8578)

Relative Risk (95% CI; p: n = events)

Reduction with Programme

Increase with Programme

*

**

0.2 0.5 1

Primary VTE Deaths at 90 days 0.61 (0.48, 0.79; p=0.0002: n=512)

VTE related deaths at 90 days 0.74 (0.61, 0.90; p=0.003: n=874)

Reduction with Programme

Patients < 4 days hospital stay(excluding day cases)

Relative Risk (95% CI; p: n = events)

Day cases

0.5 1 2

Primary VTE post-discharge deaths <90 days 1.00 (0.68, 1.46; p=0.99: n=192)

VTE related post-discharge deaths <90 days 0.96 (0.73, 1.25; p=0.74: n=393)

Relative Risk (95% CI; p: n = events)

Reduction with Programme

Increase with Programme

Relative Risk Reduction for DeathNon-surgical admissions

In-Hospital

Post-Discharge

Primary Post-discharge

0% 5% 10% 15% 20% 25% 30% 35% 40% 45%

P=0.04

P=0.006

P=0.001

% Risk Reduction

0.2 0.5 1 2 5

Total Primary VTE related deaths 0.71 (0.41, 1.25; p=0.232: n=82)

Total VTE related deaths 0.89 (0.66, 1.20; p=0.429: n=305)

Primary VTE related inhospital deaths 0.86 (0.20, 3.63; p=0.839: n=14)

VTE related inhospital deaths 1.05 (0.68, 1.62; p=0.83: n=141)

Primary VTE Deaths at 90 days 0.69 (0.38, 1.25; p=0.220: n=68)

VTE related deaths at 90 days 0.77 (0.52, 1.14; p=0.191: n=164)

VTE related Readmissions 1.04 (0.82, 1.32; p=0.765: n=494)

Hip Fracture CCS Grouping

Relative Risk (95% CI; p: n = events)

Reduction with Programme

Increase with Programme

0.2 0.5 1 2

Total Primary VTE related deaths 0.61 (0.40, 0.94; p=0.025: n=152)

Total VTE related deaths 0.72 (0.57, 0.91; p=0.0054: n=512)

Primary VTE related inhospital deaths 0.70 (0.40, 1.21; p=0.202: n=92)

VTE related inhospital deaths 0.68 (0.52, 0.88; p=0.004: n=389)

Primary VTE Deaths at 90 days 0.46 (0.24, 0.90; p=0.023: n=60)

VTE related deaths at 90 days 0.73 (0.47, 1.14; p=0.163: n=123)

VTE related Readmissions 1.34 (1.08, 1.67; p=0.009: n=556)

Nervous System CCS Grouping

Relative Risk (95% CI; p: n = events)

Reduction with Programme

Increase with Programme

Estimation lives savedBased on 2011 if all hospitals achieved 90% screening rate

430

Conclusions• There is evidence to support an impact of the National VTE

CQUIN in reducing hospital associated VTE mortality but not VTE readmissions.

• The effect is also seen in patients with duration of admission <4 days.

• Further subgroup analysis is required to refine which patient groups are benefiting and which patient groups should be considered for additional interventions.