Patient Factors Associated With Prolonged Postoperative Opioid Use After Total Knee Arthroplasty.

BACKGROUND

Pain persists in a moderate proportion of patients after total knee arthroplasty (TKA). Identifying patient factors that are associated with persistent pain may lead to improved care.

PURPOSE: The purpose of the study was to identify preoperative factors associated with increased opioid prescriptions after TKA.

METHODS

A retrospective cohort study of TKAs in an integrated health-care system (January 2008-December 2011) was conducted. The number of opioid prescriptions per 90-day period after TKA (up to 1 year), was the outcome of interest. Patient risk factors that were evaluated included demographics, pain prescriptions, comorbidities, and chronic pain conditions. Multivariable Poisson regression models were employed.

RESULTS

The median age for 23,726 patients was 67 years. Before surgery, 60.0% used opioids. Three months after surgery, 41.2% of patients continued using opioids. Factors associated with greater opioid use included: younger age (odds ratio [OR] = 0.83, 95% confidence interval [CI] 0.82-0.84 per 10-year increase), liver disease (OR = 1.11, 95% CI 1.06-1.16), preoperative nonsteroidal anti-inflammatory drug use (OR = 1.09, 95% CI 1.07-1.10), anxiety (OR = 1.05, 95% CI 1.03-1.08), substance abuse (OR = 1.03, 95% CI 1.00-1.06), diabetes mellitus (OR = 1.03, 95% CI 1.01-1.05), preoperative opioid use (OR = 1.04, 95% CI 1.04-1.04), back pain (OR = 1.23, 95% CI 1.18-1.127), congestive heart failure (OR = 1.16, 95% CI 1.06-1.27), depression (OR = 1.14, 95% CI 1.09-1.18), fibromyalgia (OR = 1.10, 95% CI 1.02-1.18), hypertension (OR = 1.06, 95% CI 1.02-1.10), nonspecific chronic pain (OR = 1.06, 95% CI 1.02-1.10), black race (OR = 1.17, 95% CI 1.12-1.23), and chronic lung disease (OR = 1.05, 95% CI 1.01-1.10).

CONCLUSION

Several preoperative factors were associated with prolonged opioid use after TKA, and their identification can assist providers guide pain management. Avoidance or weaning of preoperative opioids should be considered.