To compare the incidence of otorrhea in swimming children not using ear protection with the incidence in non swimming children following placement of tympanostomy tubes.

English language publications were sought in MEDLINE (January 1966 through November 1997). The keywords were listed. Additional articles were sought from bibliographies of textbooks, review articles, source articles and through discussion with experts.

Study designs of evaluations included in the review

Prospective controlled trials of swimming and non swimming following placement of tympanostomy tubes were included if the study had two or more parallel groups, the patient was the unit of analysis and the groups were treated equally except for the rate of swimming. Follow -up periods of included studies (where stated) ranged from 2 months to 45 months. Trials whose study group did not swim were excluded.

Specific interventions included in the review

Swimming without ear protection was compared with non swimming. Some studies placed restrictions on the depth of swimming allowed. Concomitant treatment with oral or topical antibiotics was not allowed.

Participants included in the review

Children with tympanostomy tubes were studied. The mean age of children ranged from 2.67 years to 5.98 years between studies with ages ranging from 3 months to 15 years. Tympanostomy tubes included the following types: Shepherd; Shah; and Sheehy Teflon collar.

Outcomes assessed in the review

Rates of post tympanostomy tube placement otorrhea were assessed.

How were decisions on the relevance of primary studies made?

Two reviewers independently completed a checklist for each article, according to the inclusion criteria, based on the Methods section of the clinical trials.

Validity was assessed using the following criteria: source and description of patient sample; blinding; randomisation protocol; diagnostic criteria; patient exclusion criteria; compliance check; outcome criteria; statistical analysis; results presentation; and any cointerventions. Each study was independently evaluated on the validity criteria, with each item being scored from 0 to 2, and a total validity score calculated as a proportion of the maximum attainable score. Disagreements were resolved by discussion and re-evaluation.

The odds ratio (OR) with 95% confidence intervals (CI) and the rate difference (RD) with 95% CI were calculated for each study. No details were given of methods used to extract data.

How were the studies combined?

Pooled OR and 95% CI were calculated using a fixed-effect model, while pooled RD with 95% CI were calculated using a random-effects model.

How were differences between studies investigated?

Homogeneity was assessed by the Cochran Q statistic.

Five clinical trials, including 1 randomised controlled trial (RCT with 92 children), were included (619 children). Contradictions were noted in numbers quoted as present in one trial.

Average quality score was 0.525 with a range from 0.438 to 0.625 (maximum possible was 1). Most trials were credited for describing patient sample (100%); control group (100%); diagnostic criteria (100%); exclusion criteria (80%); results presentation (80%); listed explicit outcome criteria (60%); and quality of statistical analysis (60%). Conducted less often were: compliance checks (20%); randomisation (20%); and blinding (0%). In the one RCT, 15 of the children in the non swimming group self-selected to swimming with some form of ear precaution.

There was no significant difference in the incidence of otorrhea in children who swam without ear protection and non swimmers. OR = 0.8015 (95% CI: 0.5440, 1.179). RD = -5.04 (95% CI: -11.62, 1.54).

No statistically significant heterogeneity was found. Heterogeneity Q = 2.4642 (P = 0.6511).

There is no increase in the incidence of otorrhea in children who swim without ear protection compared with children who do not swim following tympanostomy.

The aims and inclusion criteria were stated, though details of intervention groups were not well defined. The search strategy was described. Validity criteria were defined. Details were given of methods used to select primary studies and assess validity. Reasons were given for exclusion of identified studies. Heterogeneity was assessed statistically. The impossibility of excluding a systematic bias due to the lack of randomisation affecting the results was discussed.

By limiting the primary studies to those published in the English language, other relevant studies may have been omitted. No attempt was made to locate unpublished studies or to assess likelihood of publication bias. More comprehensive details of the included studies would have been helpful such as baseline comparability of groups, number per treatment arm, method of ear protection used, frequency of swimming, restriction/precautions when hair-washing or bathing, and definitions used for otorrhea. Validity criteria were defined and scored but no details were given of the scoring regime.

Since only one randomised trial was identified (and the adequacy of randomisation was described as weak), concluding that the evidence available was not of sufficient quality to assess the efficacy of ear protection would seem more appropriate than the authors conclusion that ear protection is of no benefit.

Practice: The authors consider that until further research clarifies the relationship between exposure to bath water in children with tympanostomy tubes and otitis media, it would be prudent to avoid submerging the ears in bath water without ear plugs.

Research: The authors consider that future studies examining the need for water precautions should be large, randomised, controlled, blinded and with timely follow-up.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.