The Re-Evaluation of the Measurement of Pain in Population-Based Epidemiological Studies: the SHAMA Study

BACKGROUND:While many pain patients rely on pain-relieving treatments to manage their pain, pain-related research commonly quantifies pain status using validated questionnaires without taking into account that information. This will lead to an underestimate of the burden of pain in the community. To ensure a more accurate assessment of the prevalence and severity of pain, this study aimed to develop a pain management questionnaire and to assess how much population-based pain estimates change when pain management is considered.METHODS:This study was a cross-sectional population-based study in Grampian, north-east Scotland. A total of 4600 people, aged 25 years and over, were randomly selected from a population sample frame and sent a questionnaire on pain and pain management. Population estimates of pain were determined twice: with the use of standard pain status questionnaires ('current pain') and with the use of a newly developed enhanced pain status questionnaire to determine patients' estimated pain without pain management ('all pain').RESULTS:The prevalence of current pain was 50.5% (95% CI = 48.0, 52.9). Of those who reported no current pain, 11.6% (95% CI = 9.4, 13.8) reported that they would have had pain had they not managed their pain. Thus, the all pain prevalence was 56.2% (95% CI = 53.7, 58.7). This difference in prevalence rates was statistically significant (difference = 5.7%; 95% CI = 2.2, 9.2). Likewise, participants' pain severity significantly increased when they estimated their pain without pain management (p < 0.001, Wilcoxon-signed rank test).CONCLUSIONS:Failure to assess pain management information results in an underestimation of pain prevalence and severity. This should be considered in future epidemiological studies.SUMMARY POINTS:Pain management information is currently not considered for the assessment of pain in epidemiological population-based studies.Since pain management can affect people's pain status drastically, it is likely that we currently underestimate the true burden of pain in studies assessing pain.Incorporating self-reported pain management information in an epidemiological study of pain led to significantly increased estimates of both pain prevalence and pain severity.It is therefore crucial to collect and take into account people's pain management information in future studies for a more accurate measurement of pain.