Appendectomy Pain Medication Prescribing Variation in the U.S. Military Health System

Post-appendectomy opioid prescription practices may vary widely across and within health care systems. Although guidelines encourage conservative opioid prescribing and prescribing of non-opioid pain medications, the variation of prescribing practices and the probability of opioid refill remain unknown in the U.S. Military Health System.

This retrospective observational cohort study evaluated medical data of 11,713 patients who received an appendectomy in the Military Health System between January 2016 and June 2021. Linear-mixed and generalized linear-mixed models evaluated the relationships between patient-, care-, and system-level factors and the two primary outcomes; the morphine equivalent dose (MED) at hospital discharge; and the probability of 30-day opioid prescription refill. Sensitivity analyses repeated the generalized linear-mixed model predicting the probability of opioid (re)fill after an appendectomy, but with inclusion of the full sample, including patients who had not received a discharge opioid prescription (e.g., 0 mg MED).

Discharge MED was twice the recommended guidance and was not associated with opioid refill. Higher discharge MED was associated with opioid/non-opioid combination prescription (+38 mg) relative to opioid-only, lack of non-opioid prescribing at discharge (+6 mg), care received before a Defense Health Agency opioid safety policy was released (+61 mg), documented nicotine dependence (+8 mg), and pre-appendectomy opioid prescription (+5 mg) (all P < .01). Opioid refill was more likely for patients with complicated appendicitis (OR = 1.34; P < .01); patients assigned female (OR = 1.25, P < .01); those with a documented mental health diagnosis (OR = 1.32, P = .03), an antidepressant prescription (OR = 1.84, P < .001), or both (OR = 1.54, P < .001); and patients with documented nicotine dependence (OR = 1.53, P < .001). Opioid refill was less likely for patients who received care after the Defense Health Agency policy was released (OR = 0.71, P < .001), were opioid naive (OR = 0.54, P < .001), or were Asian or Pacific Islander (relative to white patients, OR = 0.68, P = .04). Results from the sensitivity analyses were similar to the main analysis, aside from two exceptions. The probability of refill no longer differed by race and ethnicity or mental health condition only.

Individual prescriber practices shifted with new guidelines, but potentially unwarranted variation in opioid prescribing dose remained. Future studies may benefit from evaluating patients' experiences with pain management, satisfaction, and patient-centered education after appendectomy within the context of opioid prescribing practices, amount of medications used, and refill probability. Such could pave a way for standardized patient-centered procedures that both decrease unwarranted prescribing pattern variability and optimize pain management regimens.