title: Hearing loss is associated with decreased nonverbal intelligence in rural Nepal.
abstract: OBJECTIVE
  To evaluate the association between adolescent and young-adult hearing loss and nonverbal intelligence in rural Nepal.
  
  
  METHODS
  Cross-sectional assessment of hearing loss among a population cohort of adolescents and young adults.
  
  
  METHODS
  Sarlahi District, southern Nepal.
  
  
  METHODS
  Seven hundred sixty-four individuals aged 14 to 23 years.
  
  
  METHODS
  Evaluation of hearing loss, defined by World Health Organization criteria of pure-tone average greater than 25 decibels (0.5, 1, 2, 4 kHz), unilaterally and bilaterally.
  
  
  METHODS
  Nonverbal intelligence, as measured by the Test of Nonverbal Intelligence, 3rd Edition standardized score (mean, 100; standard deviation, 15).
  
  
  RESULTS
  Nonverbal intelligence scores differed between participants with normal hearing and those with bilateral (p = 0.04) but not unilateral (p = 0.74) hearing loss. Demographic and socioeconomic factors including male sex; higher caste; literacy; education level; occupation reported as student; and ownership of a bicycle, watch, and latrine were strongly associated with higher nonverbal intelligence scores (all p < 0.001). Subjects with bilateral hearing loss scored an average of 3.16 points lower (95% confidence interval, -5.56 to -0.75; p = 0.01) than subjects with normal hearing after controlling for socioeconomic factors. There was no difference in nonverbal intelligence score based on unilateral hearing loss (0.97; 95% confidence interval, -1.67 to 3.61; p = 0.47).
  
  
  CONCLUSIONS
  Nonverbal intelligence is adversely affected by bilateral hearing loss even at mild hearing loss levels. Socio economic well-being appears compromised in individuals with lower nonverbal intelligence test scores.
authors.affiliation: *Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine; and †Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; ‡Department of Urban and Environmental Policy, Occidental College, Los Angeles, California; §Department of Audiology, Kennedy Krieger Institute, Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, U.S.A.; ║Nepal Nutrition Intervention Project-Sarlahi; and ¶Speech and Hearing Unit, Ganesh Man Singh Memorial ENT Centre, Tribhuvan University Institute of Medicine, Kathmandu, Nepal.
authors.forename: Susan D
authors.initials: SD
authors.lastname: Emmett
authors.forename: Jane
authors.initials: J
authors.lastname: Schmitz
authors.forename: Joseph
authors.initials: J
authors.lastname: Pillion
authors.forename: Lee
authors.initials: L
authors.lastname: Wu
authors.forename: Subarna K
authors.initials: SK
authors.lastname: Khatry
authors.forename: Sureshwar L
authors.initials: SL
authors.lastname: Karna
authors.forename: Steven C
authors.initials: SC
authors.lastname: LeClerq
authors.forename: Keith P
authors.initials: KP
authors.lastname: West
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D005260:Female; D006312:Hearing Loss, Bilateral / Q000150:complications* / Q000453:epidemiology; D046088:Hearing Loss, Unilateral / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D008297:Male; D009390:Nepal / Q000453:epidemiology; D015995:Prevalence; D012424:Rural Population; D012959:Socioeconomic Factors; D055815:Young Adult