Efficacy and Safety of Celecoxib/Acetaminophen Versus Celecoxib for Diagnosed Osteoarthritis in Acute Exacerbation

Comparison of the proportion of patients in each treatment group who, based on the baseline assessment, achieved a response according to the OMERACT-OARSI criteria at Weeks 1, 2, 4, and 6 of follow-up.

OMERACT (Outcome Measures in Rheumatology) and OARSI (Osteoarthritis Research Society International) jointly developed a core outcome set (COS) for clinical trials in hip and knee osteoarthritis. This COS includes four key domains that should be assessed in all trials: pain, physical function, patient global assessment, and- for studies lasting one year or more-joint imaging. In this study, patients will be evaluated by the researcher at follow-up visits occurring at Weeks 1, 2, 4, and 6.

Number of participants Number of participants reporting treatment-related adverse events, as recorded in the patient diary.treatment-related adverse events through the patient's diary record.

To describe the frequency, intensity, and causality of adverse events occurring during the clinical trial, stratified by treatment group. Adverse events will be documented by participants in their patient diaries. Each reported event will be monitored and followed up at the discretion of the investigator.

To analyze the mean change in pain scores, as measured by the WOMAC questionnaire, at Weeks 1, 2, 4, and 6 compared to baseline, by treatment group.

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a disease-specific questionnaire designed to assess physical function, pain, and stiffness in individuals with hip or knee osteoarthritis, based on their experiences over the past 48 hours. In this study, patients will be assessed by the investigator at Weeks 1, 2, 4, and 6 of follow-up.

To analyze the mean change in pain intensity, as measured by the Visual Analog Scale (VAS), at Weeks 1, 2, 4, and 6 compared to baseline, stratified by treatment group.

The Visual Analog Scale (VAS) for pain is a straight line where one end represents no pain and the other represents the worst pain imaginable. The investigator will administer the VAS at each visit to assess the patient's pain intensity. At the end of the clinical trial, the percentage change in pain scores will be calculated and compared across treatment groups.

Comparison of the proportion of subjects in each treatment group who achieve a reduction of ≥30% in pain intensity, as measured by the Visual Analog Scale (VAS), at Weeks 1, 2, 4, and 6 compared to baseline.

The Visual Analog Scale (VAS) for pain is a unidimensional measurement instrument consisting of a straight line anchored by descriptors, with one end indicating "no pain" and the other representing "the worst pain imaginable." The investigator will administer the VAS at each study visit to evaluate changes in pain intensity. The proportion of patients achieving a pain reduction of more than 30% from baseline will be documented and compared among treatment groups at Weeks 1, 2, 4, and 6.

To analyze the difference in SF-36 quality of life questionnaire scores at six weeks after the initiation of the intervention, compared to baseline, by treatment group.

The Short Form-36 (SF-36) is a generic health survey comprising 36 items designed to measure self-reported Health-Related Quality of Life (HRQoL). It evaluates multiple domains of physical and mental health and generates summary scores for both physical and mental components. In this study, the SF-36 questionnaire will be administered to each patient at baseline and again at Week 6 of follow-up.

To report the treatment adherence rate, expressed as a percentage, for each intervention group.

Therapeutic adherence will be defined by the principal investigator. Adherence to treatment will be considered adequate if the patient has taken ≥80% of the prescribed doses by the time of the corresponding evaluation.

To describe the proportion of subjects experiencing therapeutic failure during the study, stratified by treatment group.

Therapeutic failure will be defined by the principal investigator following a medical evaluation. The definition requires the presence of all the following criteria: (1) a change in pain intensity of less than 10 mm on the Visual Analog Scale (VAS), or an increase in VAS score compared to baseline; (2) adherence to treatment of ≥80%; (3) a dosing regimen of every 12 hours (i.e., subjects with dose escalation) maintained for at least 7 days; and (4) absence of comorbidities that could contribute to increased pain, such as new trauma or falls.

To report the proportion of patients requiring dose escalation during the follow-up period, stratified by treatment group.

At each study visit, dose escalation (one tablet or capsule every 12 hours) may be considered for patients in any of the three treatment arms who meet the following criteria: A decrease of less than 10 mm, no change, or an increase in pain intensity on the Visual Analog Scale (VAS) compared to the previous visit. Treatment adherence of ≥80%.