Reliability, validity, and responsiveness of the Western Ontario and McMaster Universities Osteoarthritis Index for elderly patients with a femoral neck fracture

BACKGROUND

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) has been extensively evaluated in groups of patients with osteoarthritis, yet not in patients with a femoral neck fracture. This study aimed to determine the reliability, construct validity, and responsiveness of the WOMAC compared with the Short Form-12 (SF-12) and the EuroQol 5D (EQ-5D) questionnaires for the assessment of elderly patients with a femoral neck fracture.

METHODS

Reliability was tested by assessing the Cronbach alpha. Construct validity was determined with the Pearson correlation coefficient. Change scores were calculated from ten weeks to twelve months of follow-up. Standardized response means and floor and ceiling effects were determined. Analyses were performed to compare the results for patients less than eighty years old with those for patients eighty years of age or older.

RESULTS

The mean WOMAC total score was 89 points before the fracture in the younger patients and increased from 70 points at ten weeks to 81 points at two years postoperatively. In the older age group, these scores were 86, 75, and 78 points. The mean WOMAC pain scores before the fracture and at ten weeks and two years postoperatively were 92, 76, and 87 points, respectively, in the younger age group and 92, 84, and 93 points in the older age group. Function scores were 89, 68, and 79 points for the younger age group and 84, 71, and 73 points for the older age group. The Cronbach alpha for pain, stiffness, function, and the total scale ranged from 0.83 to 0.98 for the younger age group and from 0.79 to 0.97 for the older age group. Construct validity was good, with 82% and 79% of predefined hypotheses confirmed in the younger and older age groups, respectively. Responsiveness was moderate. No floor effects were found. Moderate to large ceiling effects were found for pain and stiffness scales at ten weeks and twelve months in younger patients (18% to 36%) and in the older age group (38% to 53%).

CONCLUSIONS

The WOMAC showed good reliability, construct validity, and responsiveness in both age groups of elderly patients with a femoral neck fracture who had been physically and mentally fit before the fracture. The instrument is suitable for use in future clinical studies in these populations.

CLINICAL RELEVANCE

The results are based on two clinical trials. The questionnaires used concern pure, clinically relevant issues (ability to walk, climb stairs, etc.). Moreover, the results can be used for future research comparing clinical outcomes (or treatments) for populations with a femoral neck fracture.

Condom use self-efficacy: effect on intended and actual condom use in adolescents

PURPOSE

To investigate aspects of adolescents' condom use self-efficacy that affect their intended and actual condom use.

METHODS

Four hundred twenty-four male and female sexually experienced and inexperienced adolescents with a mean age of 17.0 years filled out a questionnaire concerning condom use self-efficacy and intended and actual condom use. Specific condom use self-efficacy scales were constructed from 37 items on the basis of a principal component analysis. The effect of self-efficacy, both as a global measure and in terms of specific scales, on condom use intention and consistency was assessed using multiple hierarchic regression analyses.

RESULTS

Six specific self-efficacy scales were constructed: Technical Skills, Image Confidence, Emotion Control, Purchase, Assertiveness, and Sexual Control. In sexually inexperienced adolescents, global self-efficacy explained 48%, the six self-efficacy scales 30%, and both together 51% of the variance in intention, after statistical control for gender, age, and education level. In the sexually experienced sample, this was 40%, 50%, and 57% for intention, and 23%, 29%, and 33% for consistency of condom use. Significant predictors of intention in the final model were gender, age, global self-efficacy and purchasing skills in the inexperienced sample, and global self-efficacy, emotion control, assertiveness, image confidence, and sexual control in the experienced sample, whereas gender, age, global self-efficacy, emotion control, assertiveness, and purchase predicted consistency of condom use in the experienced sample.

CONCLUSIONS

Condom use self-efficacy is a multidimensional construct. Intended and actual condom use in adolescents are best predicted by self-efficacy measures that include both global and relevant specific aspects of condom use.