Validation of the Spanish version of the modified Harris score

Modified Harris Hip Score (HHS) is one of the most used scales in the assessment of patients with hip pathology. Although a Spanish cross-cultural adaptation has been recently published, there are many studies supporting its validity yet. Therefore, the aim of this study is to validate the newly adapted Spanish version of the HHS (ES-EHM), comparing it with the WOMAC scale.

The ES-EHM scale was applied to 100 patients who underwent a total hip replacement, in three different situations: (1) prior to surgery (pre-surgical ES-EHM), (2) after surgery, with at least 2 years of follow up (after surgery ES-EHM), and (3) 6 months after the postsurgical registration (final ES-EHM). WOMAC questionnaire was also applied once. We analyzed data of scale main score, pain score, function-related score as well as the mean of pre-surgical, postsurgical and final postsurgical ES-EHM scale, in both the ES-EHM and the WOMAC scales. Parameters of reliability, validity and sensitivity to change were obtained.

Clinically relevant improvement was observed (46.55 points) when comparing pre-surgical and post-surgical ES-EHM scores. However, no differences between postsurgical and final ES-EHM were detected. Even so, strong correlation was obtained between the following: (1) postsurgical ES-EHM and final ES-EHM scores, (2) ES-EHM and WOMAC scores, and (3) pain and function-related parameters of ES-EHM and WOMAC scores. Standardized response mean (SRM) was 2.99, test-retest reliability expressed by the intraclass correlation coefficient was 0.90 and Cronbach index 0.95.

The Spanish cross-cultural adaptation of the EHM scale shows to be reliable, valid and sensitive to change. Thus, the Spanish medical staff will be able to apply the ES-EHM scale with good scientific support.