The effect of patient factors on opioid use after anatomic and reverse shoulder arthroplasty

Background: Prolonged opioid use can lead to suboptimal outcomes after total shoulder arthroplasty (TSA), and thus, reduced consumption is desirable. Our primary aims were to determine if differences in total morphine equivalent doses existed owing to (1) age less than or greater than 65 years, (2) sex, and (3) TSA type – reverse or anatomic total shoulder arthroplasty. We also characterized potential risk factors for (1) visiting another provider for pain, (2) pain control 6 weeks postoperatively, and (3) needing an opioid refill. Methods: A retrospective cohort study of 100 patients who underwent TSA (reverse total shoulder arthroplasty N₁ = 50; anatomic total shoulder arthroplasty N₂ = 50) between 1 July 2018 and 31 December 2018 was performed. Demographics, perioperative treatments, and postoperative opioid prescriptions were recorded. Primary hypotheses were evaluated with Wilcoxon-Mann-Whitney testing. Univariate and multivariate analyses assessed potential risk factors for the 3 outcomes of interest. Results were given in adjusted odds ratios (aORs), 95% confidence intervals (CIs), and P values. Results: There was a difference (P = .009) in total morphine equivalent doses used (in 5-milligram oxycodone tablets) between patients who were younger than 65 years of age (median: 83 tablets, interquartile range: 62-140) and those who were older than 65 years of age (median: 65 tablets, interquartile range: 52-90). Unemployment (aOR = 4.68, CI: 1.5-14.2, P = .006) and age less than 65 years (aOR = 4.18, CI: 1.6-11.2, P = .004) were independent risk factors for inadequate pain control 6 weeks postoperatively. Two independent risk factors for needing an opiate prescription refill after discharge were unemployment (aOR = 4.56, CI: 1.5-13.8, P = .007) and preoperative opiate use (aOR = 3.95, CI: 1.4-11.0, P = .009). Conclusion: After TSA, morphine equivalent dose usage is higher for patients younger than 65 years of age, and several risk factors exist for requiring a refill and having inadequate pain control 6 weeks postoperatively. Prospective studies using these data to guide interventions may be beneficial.