Reliability of patient reports on compliance.

The reliability of subjective estimates of patient appliance wear plays a critical role in scientific research on compliance just as in everyday orthodontic practice. This problem was subjected to scrutiny by means of the recently developed electronic timing device and psychological investigations. Over several months 53 patients between 9 and 14 years of age treated with bionators were followed. Included were objective measurement of wearing time, judgements on compliance by patients, parents, and orthodontists, and questioning about numerous treatment-related and personality variables. These data allowed an assessment of subjective reports. Asked to classify patients as 'good', 'average', or 'poor' co-operators, neither the orthodontists nor the patients in their self-ratings exceeded 43 per cent of hits. From a heuristic model of how misjudgements on compliance arise, indicators were derived to represent certain stages of cognition formation in the patient. A strong association was found between actual compliance and patient credibility, in that generally 'poor co-operators' grossly overstate their wearing time. Consequently, various patient characteristics and features of operator-patient interaction proved significantly correlated with both criteria. Among them, regularity of wear and duration of treatment are most influential. Moreover, patient credibility appeared to be a salient point of the reciprocal perceptions of treatment partners and their personalities. The reliability of patient statements also depends upon: (1) how detailed the operator's questions are; (2) whether he draws his own conclusions from the information received instead of leaving them to the patient. This evidence may lead to greater accuracy in gauging patient compliance.