We explored the associations between opioid dose and multiple measures of pain.
Study Design and Measures:
Thirty-two consecutive patients admitted solely for an acute exacerbation of cancer-related pain or for surgery were followed for their entire hospital stay (115 days of pain). For each hospital day, we collected pain scores, the number of pain scores, trends in pain scores, the percentage of time patients had 100% acceptable relief from pain, and the number of times patients were asked about acceptable pain relief. Finally, we asked those who had 100% relief of pain whether they could have used more pain medicine. Linear regression models were fit to estimate the amount of variation explained (R2) in dose of medication, by each pain measurement variable.
Nineteen patients with cancer (74 days of pain) and 13 patients undergoing surgery (41 days of pain) were evaluated. Pain scores, the number of pain scores, trends in pain scores, and 100% acceptable relief scores poorly correlated with the use of medication in the linear regression models (R2 for all models ≤0.2). A question about needing more pain medicine explained the greatest amount of variation in opioid dose.
Pain and acceptable relief scores do not adequately reflect the use of medication. A prospective study is needed to further assess the value of additional measures of the adequacy of pain care.