Value of serum procalcitonin as an early predictor of antibiotic treatment response in inpatients with pelvic inflammatory disease (VALID)

Abstract Objective This study aimed to investigate the value of serum procalcitonin as an early predictor of antibiotic treatment response in the inpatient management of pelvic inflammatory disease (PID). Materials and methods A prospective observational study was carried out at a university hospital. Patients admitted for pelvic inflammatory disease were classified into 2 groups: responders and non-responders. The primary outcome measure was the serum level of procalcitonin at the time of admission. The secondary outcome measures were other serum inflammatory markers including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and white blood cell (WBC) count. Results Baseline characteristics were similar between the groups. Serum level of procalcitonin at the time of admission did not differ between the groups (P = 0.564). However, the non-responders had more elevated CRP and ESR compared to the responders (P = 0.045 and P = 0.030, respectively). CRP showed the highest accuracy of 72.1% (95% confidence interval [CI], 59.2 to 82.9) in predicting antibiotics response, while procalcitonin showed the lowest accuracy of 49.1% (95% CI, 35.1 to 63.2). Conclusion Compared with standard inflammatory markers such as CRP or ESR, procalcitonin had limited diagnostic value in predicting antibiotics response in patients admitted for PID. Therefore, procalcitonin measurement cannot be recommended as a laboratory test for patients with PID and the value of its routine use remains inconclusive.