Utility values among myopic patients in mainland China

Utility for Uncorrected Refractive Errors in Adolescent Schoolchildren in Kakamega County, Kenya

SIGNIFICANCE

Uncorrected refractive errors (UREs) present an enormous lifetime burden in children. Despite this, there is a dearth of knowledge on URE-related preference-based quality of life (QoL) in East Africa. This study demonstrates the positive impact of interventions on UREs; hence, it provides an empirical justification for advocacy to improve the QoL of children with URE.

PURPOSE

This study investigated the preference-based QoL (utility) for URE in school-going adolescents of Kakamega County, in Kenya.

METHODS

An observational cross-sectional study with multistage sampling was conducted on randomly selected secondary school adolescents. School-going adolescents in Forms 1 to 4 were clinically examined for the presence of URE and classified according to their URE types. Pre-screened students who met the selection criteria were classified into two groups: URE and normal sight. Participants in the normal-sight group were randomly selected from among screened students without URE. Selected participants were administered a previously validated adolescent-specific utility weighting instrument-Assessment of Quality of Life-Six Dimensions.

RESULTS

A total of 330 participants aged 17.32 ± 1.60 years (URE, 17.50 ± 1.58 years; normal-sight, 17.15 ± 1.61 years) were included in the study. The mean utility score, as elicited by the Assessment of Quality of Life-Six Dimensions scoring algorithm, was better in the normal-sight group (URE, 0.496 ± 0.22; normal sight, 0.567 ± 0.25) at baseline, whereas the reverse was true at follow-up (URE, 0.655 ± 0.20; normal sight, 0.603 ± 0.25). In all cases, the differences were significant ( P < .05); however, there was no significantly better ( P > .05) utility elicited by any URE subtype at any given time point. Nonetheless, the URE group showed significantly better utility ( P < .05) after spectacle correction.

CONCLUSIONS

Uncorrected refractive errors are associated with reduced utility in school-going adolescents, regardless of URE subtype. Spectacle correction resulted in a significantly improved utility for those with URE. Thus, this study recommends early public health strategies and spectacle interventions in schools for adolescents with URE.

Psychometric properties and comparison of four health utility approaches among myopia patients in China

BACKGROUND

The increased prevalence of myopia creates and earlier age of onset has created public health concerns for the long-term eye health, vision impairment and carries with it a significant economic burden. The quality of the economic evaluation is dependent on the sensitivity and validity of the approaches. Nowadays, there are many approaches to measure patients' health state utility (HSU). However, little is known regarding the performance of direct approach and indirect approach in people with myopia. This study is aimed to compare the psychometric properties of four HSU approaches among patients with myopia in mainland China, including two direct approaches (TTO and SG), the generic preference-based measures (PBM) (AQoL-7D) and the disease-specific PBM (VFQ-UI).

METHODS

A convenience sampling framework was used to recruit patients with myopia who attended a large ophthalmic hospital in Jinan, China. Spearman's rank correlations coefficient was used to assess concurrent validity. Known-group validity was analyzed by: (1) whether the patients wear corrective devices; (2) severity of myopia as low or moderate to high of the better eye; (3) duration of myopia as ≤ 10 years or > 10 years. Effect size (ES), relative efficiency (RE) statistic and the largest area under the receiver operating characteristic curve (AUC) were used to assess sensitivity. The intra-class correlation coefficient (ICC) and Bland-Altman plots were used to assess agreement.

RESULTS

A valid sample size of 477 myopia patients was analyzed (median duration: 10 years). The mean HSU scores between TTO and SG were similar (0.95) and higher than AQoL-7D (0.89) and VFQ-UI (0.83). Overall, the VFQ-UI had the best performance based on the psychometric analysis. The agreement indicated that there was no pair of approaches that could be used interchangeably.

CONCLUSIONS

The VFQ-UI showed better psychometric properties than other three approaches for providing health state utility in Chinese myopia patients. Given the widespread use and its generic nature of the AQoL-7D, it could be used alongside with VFQ-UI to provide complementary health state utility from a generic and disease-specific perspective for economic evaluation. More evidence on the responsiveness of four health utility approaches in myopia patients is required.

IMI Impact of Myopia

The global burden of myopia is growing. Myopia affected nearly 30% of the world population in 2020 and this number is expected to rise to 50% by 2050. This review aims to analyze the impact of myopia on individuals and society; summarizing the evidence for recent research on the prevalence of myopia and high myopia, lifetime pathological manifestations of myopia, direct health expenditure, and indirect costs such as lost productivity and reduced quality of life (QOL). The principal trends are a rising prevalence of myopia and high myopia, with a disproportionately greater increase in the prevalence of high myopia. This forecasts a future increase in vision loss due to uncorrected myopia as well as high myopia-related complications such as myopic macular degeneration. QOL is affected for those with uncorrected myopia, high myopia, or complications of high myopia. Overall the current global cost estimates related to direct health expenditure and lost productivity are in the billions. Health expenditure is greater in adults, reflecting the added costs due to myopia-related complications. Unless the current trajectory for the rising prevalence of myopia and high myopia change, the costs will continue to grow. The past few decades have seen the emergence of several novel approaches to prevent and slow myopia. Further work is needed to understand the life-long impact of myopia on an individual and the cost-effectiveness of the various novel approaches in reducing the burden.