Identifying risk groups of infectious spondylitis in patients with end-stage renal disease under hemodialysis: A propensity score-matched case-control study

Background: Patients with end-stage renal disease (ESRD) under hemodialysis (HD) are at greater risks of infectious spondylitis (IS), but there is no reliable predictor that facilitate early detection of this relatively rare and insidious disease. Methods: A retrospective review of the medical records from patients with ESRD under HD over a 12-year period was performed at a tertiary teaching hospital, and those with a first-time diagnosis of IS were identified. A 1:4 propensity score-matched case-control study was carried out, and baseline characteristics, underlying diseases, and laboratory data were compared between the study group and the control group, one month before the date of diagnosis or the index date respectively. Results: A total of 16 patients with IS were compared with 64 controls. After adjustment, recent access operation (odds ratio [OR], 13.27; 95% confidence interval [CI], 3.53 to 49.91; p < 0.001), degenerative spinal disease (OR, 12.87; 95% CI, 1.89 to 87.41; p = 0.009), HD through a tunneled cuffed catheter (OR, 6.75; 95% CI, 1.74 to 26.14; p = 0.006), low serum levels of hemoglobin, albumin, as well as high levels of red blood cell volume distribution width (RDW), alkaline phosphatase (ALP), and high sensitivity C-reactive protein were significant predictors for a IS diagnosis one month later. Receiver operating characteristic curves for hemoglobin, RDW, ALP, and albumin all showed good discrimination. The further multivariate models identified both high serum ALP levels and low serum RDW levels following a recent access intervention in patients with relatively short HD vintages may be indicative of the development of IS. Conclusion: Patients under HD with relatively short HD vintages showing either elevated ALP levels or low RDW levels following a recent access intervention should prompt clinical awareness about IS for timely diagnosis.