As United States (US) healthcare expenditures continue to rise, policymakers have sought to reduce costs while maintaining a high standard of care [1]. In spine surgery, a number of quality metrics have emerged to assess efficiency of healthcare delivery, such as extended hospital length of stay (LOS) and non-routine discharge (NRD) [2], [3], [4], [5], [6], [7], which have been associated with higher healthcare costs [2], [5], [6], [8], perioperative complications [2], [6], [9], and mortality [2], [6]. More specifically, in patients undergoing spine surgery for adult spinal deformity (ASD), extended LOS and NRD have been associated with higher rates of adverse events (AEs) [10], greater treatment costs [11], [12], and inferior long-term recovery [10]. Additionally, high perioperative opioid consumption has been associated with suboptimal postoperative outcomes and increased healthcare resource utilization following spine surgery. For example, in a retrospective study of 1428 patients who underwent spine surgery for a number of indications, Mohanty et al. found that increasing postoperative opioid use, as quantified and standardized by morphine milligram equivalents (MME), was associated with progressively longer hospital stays [13]. Given that the rate of ASD surgery has grown rapidly in recent years, from 4.16 per 100,000 adults in 2001–13.90 per 100,00 adults in 2013 [12], identifying risk factors contributing to inferior care and increased healthcare cost in this population is necessary.

Aging is associated with a number of physiologic changes which predispose elderly patients to poor wound healing, malnutrition, age-related muscle wasting (sarcopenia), and frailty, all of which have been shown to portend poor outcomes in spine surgery [14], [15], [16], [17], [18], [19]. Importantly, over 50 % of patients hospitalized with ASD are >65 years old [20], [21], [22], making the elderly population with ASD of increased concern, particularly as US life expectancy rises. In retrospective study of 13,257 patients with symptomatic lumbar stenosis/spondylolisthesis who underwent decompression and fusion, Adogwa et al. found that, among elderly patients, increased postoperative opioid use was associated with increased 90-day readmission rates and increasing management costs [23]. While few have studied elderly patients undergoing deformity correction for ASD, these patients have been shown to be at increased risk for complications, mortality, and high hospital costs [20], [21], [22], [24], [25], [26] Given the aging population, it is important to ascertain the impact of aging on surgical outcomes and healthcare resource utilization in patients with ASD.

The aim of this study was to assess the impact of geriatric status on inpatient narcotic consumption and healthcare resource utilization in patients undergoing spinal fusion for ASD.