Prevalence of previously unknown elevation of glycosylated hemoglobin in spine surgery patients and impact on length of stay and total cost

Abstract

Elevated levels of glycosylated hemoglobin (HbA1c) among spine surgery patients may have an impact on length of stay (LOS) and healthcare cost. We retrospectively reviewed the charts of 556 spine surgery patients who underwent 1 of 3 types of surgery: lumbar microdiscectomy (LMD), anterior cervical decompression and fusion (ACDF), and lumbar decompression and fusion (LDF). Information was collected about their diabetes mellitus (DM) history and HbA1c levels. We used HbA1c 6.1% as the screening cutpoint. Percentages of nondiabetic patients, those with subclinical elevation of HbA1c and those with already known DM were calculated and statistical analysis was applied. After excluding the small group of well-controlled DM (n = 14), 72.4% of patients were nondiabetic, 14.3% were subclinical patients with previously unknown HbA1c elevation, and 13.3% were already known, confirmed DM patients. There were significant differences in the LDF group between the "No DM" and "Subclinical" groups (P < 0.05) in terms of cost and LOS (P < 0.05). Age and body mass index (BMI) were very significant predictors of total cost in spine surgery patients (P <or= 0.001), in addition to the type of surgery. Univariate analysis with age, BMI, or both as covariates deprived DM-HbA1c status of statistical significance (P > 0.05) in determining cost. There is a significant segment of spine surgery patients who were unaware of their elevated HbA1c status before their preoperative visit. These patients seem to utilize more healthcare resources, which is especially evident in the LDF group. We believe that HbA1c should be considered in the routine preoperative workup of spine surgery patients.