Effectiveness assessment of otosclerosis surgery

The epidemiological characteristics of otosclerosis and its treatment in Andalusia resemble those of other populations with similar socioeconomic levels. Two complementary approaches, such as questionnaires and pure-tone audiometry, are required to assess the effectiveness of otosclerosis surgery (OS) reliably and precisely.

We describe a new method to assess effectiveness in OS. It is based on the results of pure-tone audiometry and a specially designed quality of hearing questionnaire (QHQ). The objectives of the study are: (i) to report the general epidemiologic profile of otosclerosis in Andalusia; (ii) to study the effectiveness of OS in our community using conventional methods; and (iii) to study the outcomes of OS using the QHQ and to compare them to those obtained using conventional methods.

All 31 hospitals in the public healthcare system of Andalusia were studied. They were graded into four groups using a specially designed grouping system. The data were obtained from the minimum basic dataset. The prevalence of otosclerosis in Andalusia was calculated from the incidence data, the duration of the disease and life expectancy. To assess the effectiveness of OS, 475 clinical records from 15 hospitals representing all 4 groups were analysed. Effectiveness was assessed by conventional methods, using data obtained from pure-tone audiometry, and by using version 1.02 p of the QHQ.

The incidence of clinical otosclerosis was 5.67 patients/100,000 inhabitants/year. The calculated prevalence was 0.287%. The number of cases increased progressively during the study period (p<0.001). The 15-45-year age group was the largest (62.2%) and 68.4% of patients were females. The most frequent type of otosclerosis was estapediovestibularis (fenestral), non-obliterative (91.8%). Only 48 cases (2.3%) of cochlear and 45 (2.2%) of obliterative otosclerosis were reported. The most frequently employed therapeutic procedures were stapedectomy and stapedotomy (75.70%). The average total and preoperative lengths of stay were 3.59 and 1.04 days, respectively. There were significant differences between the different types of otosclerosis. Improvement in the air-bone gap was 15.37+/-1.19 dB (n=164) and the overclosure or operative damage was 0.49+/-0.85 dB (n=164). A gap improvement of 10-40 dB was observed in 61.4% of patients. The > 65 years age group showed the best gap improvement but the largest variability. The quality of hearing measured by the QHQ showed that, in general, a better gap improvement was associated with a higher quality of hearing (Pearson correlation r=0.183; p<0.05). The 15-45-year age group had the worst gap improvement but, in contrast, the better quality of hearing.