Predicting Opioid-Dependence Using Pain Intensity And Length Of Pain Suffering In Pre-Spine-Surgery Patients

摘要

Introduction: The purpose of this study was to evaluate the diagnostic value of pain intensity and length of pain suffering as OD markers. Methods 150 patients pre-spine-surgery who were on opioids were questioned preoperatively to determine OD based on the WHO guidelines. Logistic regression analysis was used to identify the most significant factors-predictors of OD status in pre-spine-surgery patients. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) and efficiency for different pain-related parameters were calculated in accordance with standard formulas. Receiver operating characteristic (ROC) curves were obtained using SPSS. Results 30 (20%) patients met the WHO criteria for OD. We excluded those with missing pain data and out of 132 pre-spine-surgery patients 29 (22%) were OD. Using logistic regression analysis we proved that pain-related parameters were the only significant predictors of OD status in pre-spine-surgery patients with WRI showing the highest significance (p=0.003). Other variables like type of surgery, gender, race and number of previous spine surgeries showed no significance. Sensitivity and specificity for pain intensity ≥8 were 76% and 45% respectively. PPV, NPV and efficiency were 28%, 80% and 52% respectively. Sensitivity and specificity for ≥24 months pain suffering were 48% and 57% respectively. PPV, NPV and efficiency were 24%, 80% and 55% respectively. The average value of the WR index for OD patients was 660. Sensitivity and specificity for the WR index ≥660 were 34% and 92% respectively. PPV, NPV and efficiency were 56%, 83% and 80% respectively. The WR index ROC curve most closely followed the left-hand border. Conclusions Chronic pain and prolonged use of opioids raise the risk of OD in pre-spine-surgery patients to 20-22%. Pain-related parameters are significant predictors of OD status in this category of patients. On the other hand, pain intensity ≥8 and length of pain suffering ≥24 months do not have sufficiently high sensitivity and specificity. The WR index ≥660 has a very high specificity as marker for OD. It also proved to be the most accurate/efficient. However, the low positive predictive values for all these parameters make them unreliable as screening markers for OD in pre-spine-surgery patients. Introduction Predicting opioid-dependence (OD) in patients with chronic nonmalignant pain is a clinical challenge to clinicians. To date, most decisions about opioid prescriptions and patients' behaviors are based on unexamined or erroneous assumptions, without empirically validated guidelines or markers. A biopsychosocial approach1 to this problem has been suggested. It depends on the use of multiple sources of information in multiple areas to gain a comprehensive understanding of the problem. However, with addiction, it is difficult to predict who will go on to develop problems even if the patient does not seem on the initial comprehensive evaluation to be at risk. Continued monitoring can prevent any potential problems that might develop. Fortunately, a patient who has started an opioid medication can be switched, if necessary, to nonopioid alternatives early in the treatment. A screening marker that could help guide a clinician's judgment about who may be at risk for problematic opioid behavior would be of great value. Currently, however, there are virtually no widely used or accepted markers to screen for potential problematic opioid behavior in chronic pain patients. Turk and Okifuji2 examined the factors that influenced a physician's decision to prescribe opioids to patients attending a multidisciplinary pain treatment center. Overt pain behaviors seemed to have the major influence on a physician's decision to prescribe opioids even though patients were comparable with regard to other psyhosocial and physical variables. They also highlighted the fact that opioid medication may serve as a reinforcer for pain behavior such that patients who receive opioids co