Background: Knee osteoarthritis [OA] is one of the most common orthopedic diseases in Thailand. Glucosamine sulfate is an option for treatment of mild to moderate knee OA; however, this optional treatment has been restricted under the reimbursement protocol of the Comptroller General's Department [CGD]. The objective of this preliminary study was to evaluate both patient-reported and performance-based
benefits of glucosamine for the treatment of knee OA when administered as specified by the CGD reimbursement protocol.

Materials and Methods: We prospectively evaluated 100 knee OA patients who had been prescribed glucosamine sulfate and met CGD criteria for reimbursement. Outcomes of treatment were evaluated using conventional subjective measurements, including the Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], visual analog scale [VAS] for pain, and the Short form-12 [SF-12]. In addition, all patients had to complete two functional performance measures, the Timed Up and Go Test [TUGT] and the 5-time sit to stand [5XSST]. Measurements of all parameters were performed at pretreatment then again at week 6, 12, and 18.

Results: Patients were divided in to into 3 groups according to Kellgren and Lawrence system: mild OA (KL 1), moderate OA (KL 2-3), and severe OA (KL 4) in accordance with the CGD reimbursement protocol. At the 18-week follow-up [FU], 57 of the 100 patients (50 females and 7 males) had
completed evaluations of all parameters. Fifteen of the 57 patients were in the mild group (KL 1), 32 were in the moderate group (KL 2-3), and 10 were in the severe group (KL 4). The patients' mean age was 68.28 years, and the mean BMI was 26.03 kg/m2. At the 18-week FU, values of all
investigated parameters had significantly improved. However, improvement of the conventional clinical subjective parameters occurred later than those of objective functional performance, including TUGT improved from week 6; VAS, SF-12 (PCS), and 5XSST from week 12; and WOMAC and SF-12
(MCS) from week 18.

Conclusion: At the 18-week FU, glucosamine sulfate treatment of knee OA administered following the
CGD reimbursement protocol results in improvement in all evaluated parameters, especially performance-based measurements, which had no patient or surgeon bias. Whilst significant improvement was detected from week 6, at week 12, most of them were detected. Therefore, the results of this preliminary study supported the CGD reimbursement protocol, which defines that physicians have to evaluate the outcomes of treatment after 12 weeks.

Keywords: Glucosamine sulfate, Osteoarthritis, Knee, Real life, Reimbursement