Patient Demographics
Patients received an opioid prescription at 4.08% of office visits for low back pain (1,002 of 21,020 visits) (Table 1). We found significant associations between sex, race, marital status, and employment status and receipt of an opioid prescription during the visit for low back pain in our unadjusted analyses. A larger proportion of Black patients and lower proportions of Asian/Pacific Islander and patients with Other/Unknown races received an opioid prescription during the visit. A lower proportion of Hispanic patients received an opioid prescription. We did not find an association between age and receipt of an opioid prescription.
Prior Opioid Use
The majority of patients in our sample (93.4%) had no opioid use 45 days prior to the visit. Approximately 4.9% were intermittent opioid users and 1.8% were long-term opioid users prior to the visit.
Prevalence of Comorbidities and Concurrent Medication Use for Which Use of NSAIDs are Contraindicated
33.88% patient-visits had at least one comorbidity or long-term and/or concurrent prescription where NSAIDs were contraindicated. Relatively small proportions of our sample had kidney disease (5.4%), liver disease (1.8%), or inflammatory bowel disease (0.80%) (Table 2). Higher proportions had cardiovascular or cerebrovascular disease (9.9%) and gastrointestinal disorders (10.7%). A small proportion (0.4%) had chronic systemic steroid use in the previous 365 days prior to the visit. In contrast, anticoagulant or antiplatelet use was higher: 17% of individuals were chronic users in the previous 365 days prior.
Among the comorbidities, the only notable associations between a contraindication for NSAIDs and receipt of an opioid prescription during the visit were for kidney disease (9.6% who received an opioid versus 5.2% who did not), cardiovascular or cerebrovascular disease (11.1% versus 9.8%), and concurrent or long-term antiplatelet or anticoagulant use (28.8% versus 16.5%).
Comorbidities and Medication Use Associated with Higher Risk of Opioid Use Disorder or Opioid Misuse
Nearly one third of our sample (25.01%) had at least one comorbidity or concurrent medication considered a relative contraindication for opioids (Table 3): 10.0% of patients had a depression disorder diagnosis, 13.8.0% had an anxiety disorder diagnosis, and 6.1% had a substance use diagnosis. 2.6% of patients were prescribed a benzodiazepine at the office visit.
A higher proportion of those who received an opioid during the visit had depression disorders (12.6% who received an opioid vs 9.9% who did not), anxiety disorders (17.5% vs 13.9%), substance use disorders (12.7% vs 5.8%), bipolar disorder (2.7% or 1.1%) or received a prescription for a benzodiazepine during the visit (8.0% vs 2.3%).
Adjusted Odds Ratios Between Contraindications for NSAIDs and Receipt of Opioid Prescription
We estimated four separate logistic regression models (Table 4): Model 1 included the full sample of visits for low back pain, adjusting for previous opioid use (N = 24,543), models 2-4 were stratified according to opioid use prior to the office visit: no opioid use 45 days prior to the visit (N = 22,912), intermittent opioid use (N=1,165), or long-term opioid use (N=437).
Adjusted Odds of Opioid Prescription and Comorbidities and Concurrent Medication Use Associated with Contraindications for NSAIDs
Having kidney disease was associated with a three-percentage-point higher probability of receiving an opioid prescription during the primary care visit for low back pain, compared to patients with no kidney disease, after controlling for previous opioid use and other covariates (Model 1, marginal effect [ME]: 3%; 95% CI: 1%, 4%) (Table 3). This translates to 75% greater predicted probability (PP) of receiving an opioid prescription comparing individuals with kidney disease and individuals without kidney disease (7% vs. 4%). The same positive association and similar magnitude held for those who were opioid naïve (Model 2, ME: 2%, 95%CI: 1%, 4%).
Having long-term or concurrent anticoagulant/antiplatelet prescription was associated with a two-percentage-point higher probability of receiving an opioid prescription during the visit, compared to patients with no such medication use, all else equal (Model 1, ME: 2%, 95% CI: 1%, 3%). This translates to a 50% higher probability of receiving an opioid prescription between those with long-term or concurrent anticoagulant/antiplatelet use versus those without this type of medication use (6% vs. 4%). We found a similar positive association and magnitude for patients who had no prior opioid use 45 days to the visit and those with intermittent opioid use. Among intermittent and long-term users, we did not find an association between kidney disease and receipt of an opioid prescription.
Adjusted Odds of Opioid Prescription and Comorbidities and Medication Use Associated with Relative Contraindications for Opioids
Having a substance use disorder diagnosis was associated with a one-percentage-point increase in receipt of an opioid prescription at the office visit in the full sample after controlling for previous opioid use (Model 1, ME: 1%, 95% CI: 0%, 3%) and a two-percentage-point increase in the opioid naïve model (Model 2, ME: 2%, 95% CI: 1%, 3%).
The probability of being co-prescribed a benzodiazepine was positively associated with receiving an opioid prescription during the visit across nearly all models (Model 1, ME: 7%, 95% CI: 5%, 9%. This translates to a 175% greater probability of receiving an opioid prescription between those with a concurrent benzodiazepine prescription versus those without (11% PP vs. 4.0% PP). We had similar findings among patients with no opioid use 45 days prior to the office visit (Model 2, ME: 6%, 95% CI: 4%, 8%) and previous long-term use (Model 4, ME: 10%, 95% CI: 14%, 53%).
Interestingly, we found bipolar disorder was associated with a higher predicted probability of receipt of an opioid prescription among patients with intermittent opioid use (Model 3: ME: 15%, 95% CI: 0%-30%) but a significantly lower probability of receipt among patients with long-term opioid use (Model 4: ME: -15%, 95% CI: -25%- -5%).