Optimising age adjustment of trichiasis prevalence estimates using data from 162 standardised surveys from seven regions of Ethiopia

Abstract

Purpose: The prevalence of trichiasis is higher in females and increases markedly with age. Surveys carried out in the daytime, particularly in developing countries, are prone to find older individuals and females at home at the time of the survey. Population-level trichiasis estimates should adjust sample proportions to reflect the demographic breakdown of the population, although the most accurate method of doing this is unclear. Methods: Having obtained data from 162 surveys carried out in Ethiopia as part of the Global Trachoma Mapping Project from 2012 to 2015, we used internal validation with both Brier and Logarithmic forecast scoring to test stratification models to identify those models with the highest predictive accuracy. Selection of partitions was undertaken by both simple random sampling (SRS) and cluster sampling (CS) over 8192 selections. Results: A total of 4529 (1.9%) cases of trichiasis were identified from 241,139 individuals aged ≥15 years from a total of 4210 kebeles and 122,090 households visited. Overall, the binning method using 5-year bands from age 15 to 69 years, with coarser binning in 20-year age-bands above this age, provided the best predictive accuracy, in both SRS and CS methodologies and for both the Brier and Logarithmic scoring rules. Conclusion: The greatest predictive accuracy for trichiasis estimates was found by adjusting for sex and in 5-year age-bands from the age of 15 to 69 years and in 20-year age-bands in those aged 70 years and greater. Trichiasis surveys attempting to make population-level inferences should use this method to optimise surgery backlog estimates.

Prevalence and Determinants of Trachomatous Trichiasis towards Elimination of Trachoma in Ethiopia: A Systematic Review and Meta- Analysis

“…To this end, our full data evaluation accommodated 13 articles, whereof three articles were excluded for target population and irrelevancy of the content [42,46,47]. Finally, ten articles were doomed for quality appraisal, data abstraction, and narrative account and meta-analysis stages [18,[48][49][50][51][52][53][54][55][56]. For ease of data management, the data from the included studies were summarized on the bases of the rst author, year of publication, region of study, study purpose, study design, sample size, response rate, study outcome (prevalence & determinant), outcomes and outcome analyzed (Table 2).…”

“…Figure 1PRISMA ow chart to illustrate the process by which articles were selected or rejected Description of included studies Earlier studies of the included ve articles were published in 2016 [48][49][50][51][52] while the remaining three and two studies were published respectively in 2018 [53][54][55]& 2019 [18,56].Publications were distributed across the regions, and accordingly two studies were published from Amhara region [18,54]while one article published from Gambela [48], Tigray [49], Beneshangul [50], Somalia [55], Afar [53], SNNPR [52], and Oromia [51] regions with the remaining one study from wider area of the country so has labeled as national level [18]. Most of the included studies(50.0%) were published in the year 2016 [48][49][50][51][52] while there were no publications obtained and included in the year 2015, 2017 & 2020 (Figure 2).…”

“…In all the articles, data were collected at the household level within areas with a total population of 100 to 250,000 as an evaluation unit. The prevalence of trachoma with the simultaneous analysis of the prevalence of TT and TF were considered as outcomes at every evaluation unit [18,[48][49][50][51][52][53][54][55][56].…”

“…During the process of the assessment, each individual study were identi ed with the placement of scienti c & appropriate sampling method, adequate sample size, and an appropriate method of data analysis (Annex1).All reviewers appraised every article independently using the pre-prepared format. After completion of the independent work, the appraisal results were compared among reviewer that nally provided with a strong quality rating of value greater than ve (>5) for all studies as presented on the right wing of Table 2 [18,[48][49][50][51][52][53][54][55][56].…”

“…The contribution of each region to the pooled prevalence was signi cantly deferent. [56](Figure 2). On the basis of individual studies, the prevalence of TT demonstrated an unstable pattern of change over the ve years of the review period.…”