Impact of potentially inappropriate medication on surgical outcomes in older patients with lumbar spinal stenosis

Background: The administration of potentially inappropriate medications (PIMs) as well as polypharmacy in older individuals has become a medical and socioeconomic issue. Meanwhile, given that lumbar spinal stenosis (LSS) is one of the most prevalent musculoskeletal conditions, significantly affecting mobility in older adults and becoming increasingly common in aging societies, its management in this population has emerged as a critical concern. We aimed to elucidate the prevalence of PIMs among older LSS patients and identify those potentially impacting surgical outcomes. Methods: We retrospectively analyzed 296 consecutive patients aged 65 years or older who underwent LSS surgery. Based on available guidelines, 19 medication categories were considered PIMs. Pre- and postoperative health-related quality of life was assessed using the Roland-Morris Disability Questionnaire and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire. Results: The most frequently prescribed PIMs included hypnotics, steroids, antithrombotic drugs, antidiabetic drugs, laxatives, and nonsteroidal anti-inflammatory drugs in older LSS patients. Among these medications, antithrombotic drugs showed a significant association with surgical outcomes. When the subjects were divided into antithrombotic drug users (n = 57) and non-users (n = 239), no significant difference in the incidence of postoperative complications was observed between the two groups. However, 1 year after surgery, users had significantly worse walking ability than did nonusers (adjusted p value = 0.028), despite no significant differences before and 6 months after surgery. Furthermore, nonusers showed significant improvement in walking ability (p < 0.001) and social life scores (p = 0.014) from 6 months to 1 year after surgery, whereas users exhibited no significant improvements during this period. Conclusions: Among the PIMs, hypnotics, steroids, antithrombotic drugs, laxatives, antidiabetic drugs, and nonsteroidal anti-inflammatory drugs were commonly used by older LSS patients. Older LSS patients taking antithrombotic drugs are unlikely to have good surgical outcomes.