Cardiac interventions in Wales: A comparison of benefits between NHS Wales specialties

OBJECTIVES

The study aimed to assess if specialised healthcare service interventions in Wales benefit the population equitably in work commissioned by the Welsh Health Specialised Services Committee (WHSSC).

APPROACH

The study utilised anonymised individual-level, population-scale, routinely collected electronic health record (EHR) data held in the Secure Anonymised Information Linkage (SAIL) Databank to identify patients resident in Wales receiving specialist cardiac interventions. Measurement was undertaken of associated patient outcomes 2-years before and after the intervention (minus a 6-month clearance period on either side) by measuring events in primary care, hospital attendance, outpatient and emergency department. The analysis controlled for comorbidity (Charlson) and deprivation (Welsh Index of Multiple Deprivation), stratified by admission type (elective or emergency) and membership of top 5% post-intervention costs. Costs were estimated by multiplying events by mean person cost estimates.

RESULTS

We identified 5,999 percutaneous coronary interventions (PCI) and 1,640 coronary artery bypass graft (CABG) between 2014-06-01 to 2020-02-29. The ratio of emergency to elective interventions was 2.85 for PCI and 1.04 for CABG. In multivariate analysis significant associations were identified for comorbidity (OR = 1.52, CI = (1.01-2.27)), deprivation (OR = 1.34, CI = (1.03-1.76)) and rurality (OR = 0.81, CI = (0.70-0.95)) for PCI interventions, and comorbidity (OR = 1.47, CI = (1.10-1.98)) for CABG. Higher costs post-intervention were associated with increased comorbidity for PCI and CABG in the top 5% cost groups, but for PCI this was not seen outside the top 5%. For PCI, moderate cost increase was associated with increased deprivation, but the picture was more mixed following CABG interventions. For both interventions, lower costs post intervention were seen in rural locations.

CONCLUSION

We identified and compared health outcomes for selected specialist cardiac interventions amongst patients resident in Wales, with these methods and analyses, providing a template for comparing other cardiac interventions.

Cost-effectiveness analysis in colorectal cancer using a semi-Markov model

Cost and effectiveness are usually modeled according to one studied event or one health state with parametric or non-parametric methods. In this paper, we propose an original method for assessing total costs while incorporating the dynamics of change in the health status of patients. A semi-Markov model in which the distributions of sojourn times are explicitly defined is developed. The hazard function of sojourn times is modeled by Weibull distributions specific to each transition. A vector of covariates is incorporated into the hazard function of each transition. From a regression model for costs, a cumulative cost function is derived. An estimation of the mean cost per patient in each state defined in the semi-Markov model could thus be made, and this enables us to identify the determinants of direct costs. The results of incremental net benefit (INB) are assessed using the bootstrap method. A cost-effectiveness analysis is performed in order to compare two strategies of follow-up in the colorectal cancer study. Two hundred and forty patients were enrolled in this study. Three health states are defined for patients with curative resection of colorectal cancer: alive without relapse, alive with relapse, and dead. The mean survival is 4.35 and 4.12 years, respectively, in the standard and moderate follow-up groups. We show that mean cost differs significantly by follow-up strategy and Dukes stage. Finally, the INB is assessed and this indicates that neither of the strategies compared was more cost-effective than the other.