The prevalence of chronic pain and its impact on activities of daily living disability and depressive symptoms according to multiple definitions in a Japanese population: the Hisayama study

Objectives:This study aimed to compare the prevalence of chronic pain using various definitions from previous studies and to determine the optimal definition for detecting chronic pain associated with physical and emotional dysfunction in a general Japanese population.Methods:A total of 2700 community-dwelling Japanese residents aged ≥40 years were assessed for chronic pain and its components of duration, frequency, and intensity. The activities of daily living (ADL) disability and depressive symptoms of participants were also evaluated using the modified Lankin Scale and Patient Health Questionnaire-9. The odds ratios and the population attributable fractions (PAFs) for ADL disability and depressive symptoms were estimated using a logistic regression model.Results:The prevalence of chronic pain varied greatly by definition, ranging from 13% for pain defined as pain duration ≥3 months, pain frequency ≥ twice a week, and pain intensity of ≥50 mm by a visual analogue scale (VAS) to 48% for a simple definition of pain duration ≥3 months. The PAFs for ADL disability and depressive symptoms were relatively high at 33% in participants with pain duration of ≥6 months and 30% in those with pain frequency of ≥twice a week, while the VAS ≥50 mm group had a low PAF of 12%.Conclusion:For screening people with chronic pain and ADL disability or depressive symptoms, the criteria of pain duration and pain frequency yielded essentially identical results, while the criterion of pain intensity risked overlooking individuals with chronic pain and these associated symptoms.