Long-term follow-up of chronic suppurative otitis media in a high-risk children cohort.

Objective: Chronic suppurative otitis media (CSOM) is the leading cause of mild to moderate hearing impairment in children worldwide and a major public health problem in many indigenous populations. There is a lack of basic epidemiological facts and knowledge on the development of CSOM, as the disease primarily affects developing countries where research capacities often are limited. The purpose of this study was to determine the long-term outcome of CSOM in a high-risk population and to identify risk factors.

Methods: Follow-up study (2008) on a population-based cohort of 465 children in Greenland, initially examined (1996-8) between the ages 0 and 4 years. Follow-up was attempted among 307 children living in the two major towns. Binomial logistic regression analysis was made to identify risk factors for developing CSOM and for maintaining disease in to adolescence (odds ratios). Log linear binomial regression was used to estimate risk ratios and absolute risks.

Results: At follow-up 236 participated (77% of those available). The prevalence of CSOM was 32/236 (14%) at age group 0-4 years and 21/236 (9%) at age group 11-15 years. Thirteen had disease debut after the initial study. Of those with CSOM in the initial study 24/32 (75%) healed spontaneously. Risk factors for the development of CSOM at any time in childhood was the mother's history of CSOM OR 2.55 (95% CI 1.14-5.70; p=0.02), and mothers with low levels of schooling OR 1.57 (1.03-2.40; p=0.04). Once CSOM had developed boys were more likely to have persistent disease OR 5.46 (95% CI 1.47-20.37; p=0.01). The absolute risk of CSOM if the mother had both a history of CSOM and low schooling was for boys 45.4% (95% CI 26.5-77.7) and for girls 30.7% (95% CI 17.8-53.10). The cumulative risk of CSOM was 19% at follow-up.

Conclusions: Even though a large number of CSOM cases seemed to heal spontaneously, the prevalence of untreated CSOM among school-age children in Greenland remained high as new cases were found at follow-up. Increased focus on prevention and identification of children at special risk could reduce the high prevalence of CSOM.