Risk stratification of opioid misuse among patients with cancer pain using the SOAPP-SF

Opioids are recognized as an integral part of the armamentarium in the management of cancer pain. There has been a growing awareness of the misuse of prescription opioids among cancer patients. More research is needed to detail risk factors and incidence for opioid misuse among cancer pain patients.

We reviewed 522 patient charts that were seen in our Pain Center from January 1, 2009 to June 30, 2009 for risk stratification of opioid misuse with demographic and clinical factors utilizing the Screener and Opioid Assessment for Patients with Pain-short form (SOAPP-SF). Group differences based on High (≥4) and Low (<4) SOAPP-SF scores were evaluated at initial visit, follow-up within a month and 6-9 months.

One hundred forty-nine of the 522 (29%) patients had a SOAPP-SF score of ≥4. The mean age for patients with high SOAPP-SF score (≥4) was 50 ± 14 vs 56 ± 14 for patients with low SOAPP-SF score (<4) (P < 0.0001). The pain scores were higher for patients with high SOAPP-SF score compared with patients with low SOAPP-SF score at consult (P < 0.0001). Morphine equivalent daily dose (MEDD) was higher for patients with high SOAPP-SF score compared with patients with low SOAPP-SF score at consult (P = 0.0461). Fatigue, feeling of well-being, and poor appetite were higher among the high SOAPP-SF group at initial visit (P < 0.0001, <0.0001, <0.0149, respectively). The high SOAPP-SF score patients also had statistically significant (P < 0.05) higher anxiety and depression scores at all three time points. In the multivariate analysis, patients younger than 55 years have a higher odds of having a "high" SOAPP-SF score than patients 55 years and older {odds ratio (OR) (95% confidence interval [CI]) = 2.76 (1.58, 4.81), P = 0.0003} adjusting for employment status, disease status, treatment status, usual pain score, and morphine equivalency at consult. Patients with higher usual pain score at consult have higher odds of a "high" SOAPP-SF score (OR [95% CI] = 1.34 [1.19, 1.51], P < 0.0001) adjusting for age, employment status, disease status, treatment status, and morphine equivalency at consult.

Patients classified by the SOAPP-SF in the current study as high risk tended to be younger, endorse more pain, have higher MEDD requirement, and endorse more symptoms of depression and anxiety. These findings are consistent with the literature on risk factors of opioid abuse in chronic pain patients which suggests that certain patient characteristics such as younger age, anxiety, and depression symptomatology are associated with greater risk for opioid misuse. However, a limitation of the current study is that other measures of opioid abuse were not available for validation and comparison with the SOAPP-SF.