Revised estimates of leprosy disability weights for assessing the global burden of disease: A systematic review and individual patient data meta-analysis

Abstract

Background Leprosy is a chronic bacterial infection caused by Mycobacterium leprae, which may lead to physical disability, stigma, and discrimination. The chronicity of the disease and disabilities are the prime contributors to the disease burden of leprosy. The current figures of the disease burden in the 2017 global burden of disease study, however, are considered to be under-estimated. In this study, we aimed to systematically review the literature and perform individual patient data meta-analysis to estimate new disability weights for leprosy, using Health-Related Quality of Life (HRQOL) data. Methodology/principal findings The search strategy included all major databases with no restriction on language, setting, study design, or year of publication. Studies on human populations that have been affected by leprosy and recorded the HRQOL with the Short form tool, were included. A consortium was formed with authors who could share the anonymous individual-level data of their study. Mean disability weight estimates, sorted by the grade of leprosy disability as defined by WHO, were estimated for individual participant data and pooled using multivariate random-effects meta-analysis. Eight out of 14 studies from the review were included in the meta-analysis due to the availability of individual-level data (667 individuals). The overall estimated disability weight for grade 2 disability was 0.26 (95%CI: 0.18–0.34). For grade 1 disability the estimated weight was 0.19 (95%CI: 0.13–0.26) and for grade 0 disability it was 0.13 (95%CI: 0.06–0.19). The revised disability weight for grade 2 leprosy disability is four times higher than the published GBD 2017 weights for leprosy and the grade 1 disability weight is nearly twenty times higher. Conclusions/significance The global burden of leprosy is grossly underestimated. Revision of the current disability weights and inclusion of disability caused in individuals with grade 0 leprosy disability will contribute towards a more precise estimation of the global burden of leprosy.

A systematic literature review of disability weights measurement studies: evolution of methodological choices

“…Six of these studies (n = 6) used the EQ-5D model [33,35,36,39,40,61], while one study (n = 1) assessed disability weights for health conditions using the CLAMES methodology [55]. Moreover, a systematic review and meta-analysis of individual patient data obtained new estimates of leprosy disability weights based on SF-36 health-related quality of life data [17]. Thirty disability weights measurement studies (n = 30; 65%) described the health states using the disease-specific system [8, 12-16, 18-20, 34, 37, 42, 43, 45, 46, 50, 51, 53, 54, 56-60, 62-67].…”

“…The remaining nineteen studies (n = 19; 41%) concerned disability weights for specific causes or sequelae of diseases (i.e. injuries [33][34][35][36], poisonings [37], urological disease [38], periodontal disease [39], oral disease [40], infectious diseases [41], alcohol use disorders [42], mental disorders [43], stroke [44], cardiovascular disease (CVD [45];), multiple sclerosis [46], neoplasms [47,48], leprosy [17], paediatric congenital anomalies [18], or osteoporosis [49]).…”

“…In 2014, an overview of disability weight studies and their design choices was published [9]. However, since then several other disability weights measurement studies have been performed, either because a national burden of disease study was performed, with the researchers preferring to use disability weights that are based on the preferences of the national population [13][14][15][16] or because disability weights for certain diseases were unavailable [17][18][19]. Another reason may be that existing disability weights were too granular, meaning that the disability weights represent health states that are heterogeneous with respect to the severity level of functional limitations [12,20], and may therefore hamper the mapping of disability weights to available epidemiological data.…”

Guiding policy towards zero leprosy: Challenges for modelling & economic evaluation

“…DALYs are a standardized measure of disease burden, which account for the years lost due to disability and the years of life lost. However, the usage of DALYs in leprosy is usually ignored because the currently used disability weights, which only cover health loss due to general disfigurement, do not sufficiently reflect the broader consequences of leprosy 12 . For DALYs to be a valuable metric, disability weights for leprosy should be revisited, covering leprosy-specific consequences including disfigurement and mental health.…”

Evaluation of proposed cranial and maxillary bone alteration parameters in persons affected by Hansen’s disease

“…Most of the 200,000 new cases of Hansen’s disease (HD, leprosy) diagnosed each year occur in India, Indonesia and Brazil [ 1 ]. The impact of HD on individual affected persons and the overall burden on health systems is amplified by delayed diagnosis, which increases the risk of patients presenting with HD-related impairments and disabilities [ 2 , 3 ]. These can include bone alterations, particularly in the hands, feet and face [ 4 ], leading to secondary complications [ 5 ], long-term disability and diminished quality-of-life [ 6 – 8 ], and contributing to stigmatization of persons affected by HD.…”