Pre-operative anemia prior to gynecologic surgery is associated with increased healthcare costs

Objective To compare healthcare utilization costs between anemic and non-anemic patients undergoing elective hysterectomy and myomectomy for benign indications from the date of surgery to 30-days postoperatively. Design Retrospective population-based cohort study. Setting Single-payer publicly funded healthcare system in Ontario, Canada between 2013-2020. Participants Adult women (≥18 years of age) who underwent elective hysterectomy or myomectomy (laparoscopic/laparotomy) for benign indications. Interventions Our exposure of interest was pre-operative anemia, defined as the most recent hemoglobin value <12g/dL on the complete blood count measured before the date of surgery. Our primary outcome was healthcare costs (total and disaggregated) from the perspective of the single-payer publicly funded healthcare system. Results Of the 59,270 patients in the cohort, 11,802 (19.9%) had pre-operative anemia. After propensity matching, standardized differences in all baseline characteristics (N=10,103 per group) were <0.10. In the matched cohort, the mean total healthcare cost per anemic patient was higher compared to cost per non-anemic patient ($6,134.88 ± $2,782.38 vs. $6,009.97 ± $2,423.27, p<0.001). Anemic patients, compared to non-anemic patients, had a higher mean difference in total healthcare cost of $124.91 per patient (95%CI $53.54 - $196.29) translating to an increased cost attributable to anemia of 2.08% (95%CI 0.89% - 3.28%, p<0.001). In a subgroup analysis of patients undergoing hysterectomy (N=9041), the cost was also significantly higher for anemic patients (mean difference per patient of $117.67, 95%CI $41.58 - $193.75). For those undergoing myomectomy (N=1062) the difference in cost was not statistically significant (mean difference $186.61, 95%CI -$17.42 - $390.65). Conclusion Pre-operative anemia was associated with significantly increased healthcare resource utilization and costs for patients undergoing elective gynecologic surgery. Although the cost difference per case was modest, when extrapolated to the population level, this difference could result in substantially significant cost to the healthcare system, attributable to pre-operative anemia.