[Development and validation of the Chronic Otitis Media Outcome Test 15 (COMOT-15). Measurement of health-related quality of life in patients with chronic otitis media]

Abstract

Background: Clinical experience has shown that chronic otitis media (COM) affects health-related quality of life (HR-QOL) of the patients. Nevertheless, up to now no validated measurement instrument encompassing all the relevant dimensions of HR-QOL is available.

Material and methods: In phase 1 the development of the Chonic Otitis Media Outcome Test (COMOT) was conducted. A group of experts identified 31 HR-QOL concepts as being relative for COM which was reduced to 15 items (COMOT-15) by sequential statistical analysis on the basis of data from 50 consecutive COM patients. In addition to the overall score (GS), three sub-scores (ear symptoms, OS; hearing function, HF; and mental being, PB) were introduced. In phase 2 validation was performed by calculating reliability, validity, and responsiveness with the data of 121 prospectively evaluated patients.

Results: COMOT-15 showed an excellent reliability with high internal consistency (Cronbach's alpha from 0.89 to 0.91) and high retest reliability coefficients (all r>0.8). Content validity was determined by a study of the literature. COMOT-15 can distinguish COM patients from healthy subjects. Global assessment of impairment of HR-QOL by COM correlated very well with the scores of COMOT-15. However, the responsiveness of the COMOT-15 questionnaire was low.

Conclusions: COMOT-15 is a reliable, valid and sensitive instrument for measurement of HR-QOL of COM patients. The results obtained with the questionnaire can be interpreted very well by the investigator. COMOT-15 should be used in otological outcomes research.