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Observational study of the relationship between volume and outcomes using data from the National Audit of Cardiac
Patrick Doherty1, Alexander S Harrison1, Mike Knapton2
1Department of Health Sciences , University of York , York , UK.
Insights
This study found no link between patient volume and outcomes in cardiac rehabilitation (CR) programs. High-volume and low-volume centers showed similar results, suggesting no need to centralize CR services.
Area of Science:
- Cardiology
- Public Health
- Health Services Research
Background:
- Cardiac rehabilitation (CR) is a vital, evidence-based intervention.
- CR services are delivered across diverse centers with varying patient volumes.
- The relationship between CR center volume and patient outcomes remains unclear.
Purpose of the Study:
- To investigate the association between patient volume and outcomes in cardiac rehabilitation.
- To determine if higher patient volumes in CR centers correlate with improved patient outcomes.
- To assess the impact of volume on various CR outcome measures.
Main Methods:
- Utilized national audit data from 2012-2013 for 178 CR centers.
- Calculated volume based on the total number of patients entering outpatient CR.
- Employed hierarchical multiple regression, adjusting for center and patient characteristics, to analyze volume-outcome relationships for BMI, blood pressure, psychosocial well-being, cholesterol, smoking cessation, and physical activity.
Main Results:
- Analysis included 48,476 patients; average age 66 years, 70% male.
- Regression analysis demonstrated no statistically significant volume-outcome relationship in CR.
- No evidence suggests that higher patient volume leads to better outcomes.
Conclusions:
- Unlike cardiac surgery, CR patient volume does not significantly impact outcomes when adjusted for key factors.
- Findings do not support the centralization of cardiac rehabilitation services based on volume.
- This study provides a benchmark for future research on volume-outcome relationships in CR.
Objective:
Cardiac rehabilitation (CR) is an evidence-based intervention delivered by a wide range of high-volume and low-volume centres; however, the extent of volume-outcome relationship is yet to be studied. There is a lack of consensus about the effect of volume on outcomes, with evidence of mixed effects in acute and chronic care. The aim of this study is, to investigate the extent of association of outcomes in CR with patient volume.
Methods:
Data was validated and extracted from the national audit from 2012 to 2013 for each CR centre. Volume was calculated as the total number of patients entering outpatient CR. Hierarchical multiple regression models were used to test for relationships between volume and outcomes. The outcomes included body mass index, blood pressure, psychosocial well-being, cholesterol, smoking cessation and physical activity. The analyses were adjusted for centre and patient characteristics and confounders.
Results:
The number of patients included in the volume analysis was 48 476, derived from 178 CR centres. The average age per centre was 66 years with a 70% male distribution of patients enrolled. Regression analysis revealed no volume-outcome relationship, additionally no statistical significance existed.
Conclusions:
Unlike cardiac surgery this study, after accounting for staffing, age, gender and comorbidity, shows no effect of volume on outcome following CR delivered by high-volume and low-volume programmes. Based on our data there is no support for centralisation of services. Our findings and methodology can be used as a benchmark for future volume-outcome relationship studies in CR.
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