Objective: To evaluate the consistency of the questionnaires (WOMAC, Lequesne, VAS, SF 36-PCS and SF 36-MCS) when applied in patients with osteoarthritis of the knees (KOA) verifying if age and level of education interfere with the completion of the questionnaires.
Method: One hundred and two patients with KOA answered WOMAC, LESQUESNE, VAS and SF-36 questionnaires and provided data correlated with age and education. The internal consistency of the WOMAC questionnaire was verified with Cronbach's alpha. Pearson's correlations between the questionnaires, age and educational level was performed.
Results: Mean age was 65 years old. Schooling averaged 7.94 years; WOMAC 47.95; VAS 63.57; Lequesne 12.29; PCS and MCS 31.91 43.68. Cronbach's alpha for WOMAC 0.9. Education did not affect WOMAC response (r=-0.182, p = 0.067) and MCS (r=0.021 / p=0.835), but showed weak but significant correlation with VAS (r=-0.264 / p=0.007), Lequesne (r=0.277, p=0.005) and PCS (r=0.309/ p=0.002). Age showed significant direct correlation only with PCS (r=0.205, p=0.039).
Conclusion: The level of education does not interfere with the completion of WOMAC but may interfere with completing VAS, Lequesne and physical component of SF-36. Level of Evidence II, Retrospective Study.
Keywords: Knee joint; Osteoarthritis; Questionnaires.