Early Life Influences on Hearing in Adulthood: a Systematic Review and Two-Step Individual Patient Data Meta-Analysis

Abstract

Objectives: Adverse prenatal and early childhood development may increase susceptibility of hearing loss in adulthood. The objective was to assess whether indices of early development are associated with adultonset hearing loss in adults ≥18 years.Design: In a systematic review and meta-analysis, four electronic databases were searched for studies reporting associations between indices of early development (birth weight and adult height) and adult-onset hearing loss in adults ≥18 years. We screened studies, extracted data, and assessed risk of bias. Authors were contacted to provide adjusted odds ratios from a logistic regression model for relationships between birth weight/adult height and normal/impaired hearing enabling a twostep individual patient data random-effects meta-analysis to be carried out. The study is registered with PROSPERO, CRD42020152214.Results: Four studies of birth weight and seven of adult height were identified. Three studies reported smaller birth weight associated with poorer adult hearing. Six studies reported shorter height associated with poorer hearing. Risk of bias was low to moderate. Four studies provided data for two-step individual patient data random-effects meta-analysis. Odds of hearing impairment were 13.5% lower for every 1 kg increase in birth weight [OR: 0.865 (95% confidence interval: 0.824 to 0.909)] in adulthood over two studies (N=81,289). Every 1 cm increase in height was associated with a 3% reduction in the odds of hearing impairment [OR: 0.970 (95% confidence interval: 0.968 to 0.971)] over four studies (N=156,740). Conclusions:Emerging evidence suggests that adverse early development increases the likelihood of hearing impairment in adulthood.Research and public health attention should focus on the potential for prevention of hearing impairment by optimizing development in early life.

Consideration of health inequity in systematic reviews and primary studies on risk factors for hearing loss

“…Of the 17 included SRs, 10 considered physiological risk factors for hearing loss [38][39][40][41][42][43][44][45][46][47], four considered environmental risk factors [52][53][54], two considered demographic risk factors [49,50], and one considered behavioral risk factors [48]. Of the 251 primary studies, 248 were observational studies, and three were RCTs.…”

“…All 17 SRs included studies which reported gender and personal characteristics at baseline, and 15 SRs included studies which reported gender and personal characteristics in the analysis of results, although in some reviews the latter was in a small proportion of included studies [38,[41][42][43][44][45][46][47][48][49][50][51][52][53][54]. Studies reporting data on occupation were included in a total of eight SRs [38,42,45,48,49,51,53,54]. Place of residence, race/ethnicity, education, socioeconomic status, social capital and features of relationships were also reported across the included studies, albeit in fewer than 10% of studies at both baseline and in results for all criteria.…”

“…A total of 118 primary studies (38.31%) across the 17 included SRs were carried out in LMICs. Only one SR did not include any primary studies set in LMICs [49] and in one review all of the primary studies were set in LMICs [51]. Other than in Basu et al which included solely primary studies set in LMICs [51], four SRs included a majority of primary studies set in LMICs [39,44,48,50].…”

“…Of the 64 SRs included in Briscoe et al [35], 17 met the inclusion criteria for this secondary analysis (see Table 2) [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52]. Of these, seven were published in 2021, and 10 were published in 2022.…”

“…The occupation was the next most frequently reported data, including at baseline in 81 studies (32.66%) and in the results of 69 studies (27.82%) (see Table 3). All 17 SRs included studies which reported gender and personal characteristics at baseline, and 15 SRs included studies which reported gender and personal characteristics in the analysis of results, although in some reviews the latter was in a small proportion of included studies [38,[41][42][43][44][45][46][47][48][49][50][51][52][53][54]. Studies reporting data on occupation were included in a total of eight SRs [38,42,45,48,49,51,53,54].…”