Incremental cost-effectiveness of screening and laser treatment for diabetic retinopathy and macular edema in Malawi.

Damir Vetrini,Christine A Kiire,Simon P Harding,Petros C Kayange,Khumbo Kalua,Gerald Msukwa,Nicholas A V Beare,Jason Madan,Philip I Burgess,David Hutton

doi:10.1371/journal.pone.0190742

Abstract

ObjectiveTo investigate the economic impact of introducing targeted screening and laser photocoagulation treatment for sight-threatening diabetic retinopathy and macular edema in a setting with no previous screening or laser treatment for diabetic retinopathy in sub-Saharan Africa.Materials and methodsA cohort Markov model was built to compare combined targeted screening and laser treatment for patients with sight-threatening diabetic retinopathy and macular edema against no intervention. Primary outcomes were incremental cost per quality-adjusted life year (QALY) gained and per disability-adjusted life year (DALY) averted. Primary data were collected on 357 participants from the Malawi Diabetic Retinopathy Study, a prospective, observational cohort study. Multiple scenarios were explored and a probabilistic sensitivity analysis was performed.ResultsIn the base case (age: 50 years, service utilization rate: 80%), the cost of the intervention and the years of severe visual impairment averted per patient screened were $209 and 2.2 years respectively. Applying the World Health Organization threshold of cost-effectiveness for Malawi ($679), the base case was cost-effective when QALYs were used ($400 per QALY gained) but not when DALYs were used ($766 per DALY averted). The intervention was more cost-effective when it targeted younger patients (age: 30 years) and less cost-effective when the utilization rate was lowered to 50%.ConclusionsAnnual photographic screening of diabetic patients attending medical diabetes clinics in Malawi, with the provision of laser treatment for those with sight-threatening diabetic retinopathy and macular edema, appears to be cost-effective in terms of QALYs gained, in our base case scenario. Cost-effectiveness improves if services are utilized more intensively and extended to younger patients.

Highlights

In the base case, the cost of the intervention and the years of severe visual impairment averted per patient screened were $209 and 2.2 years respectively
Non-communicable diseases have a major impact on the global burden of disease, contributing 54% of all disability-adjusted life years (DALYs) lost globally [1]
It has previously been shown that at baseline in the Malawi Diabetic Retinopathy Study (MDRS), the prevalence of STDR in the patients attending hospital based diabetic clinics was estimated to be 29.4%, approximately four times that reported in recent European studies [16]

Summary

Introduction

Non-communicable diseases have a major impact on the global burden of disease, contributing 54% of all disability-adjusted life years (DALYs) lost globally [1]. Diabetes is a leading cause of morbidity and mortality in most high-income countries and its prevalence is rising rapidly in economically developing countries [2]. It causes visual impairment primarily through the development of diabetic retinopathy (DR), in particular, proliferative diabetic retinopathy (PDR) and diabetic maculopathy, which includes both macular edema and macular ischemia. Medical interventions can decrease some of the risk to vision [4,5,6,7]. If sight-threatening retinopathy (STDR) is present, timely laser photocoagulation of the retina decreases the risk of severe vision loss [8,9]

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Results

Conclusion