Table 3

Measurement and psychometric properties assessed for the FASH questionnaire

Validity testing
 Face validity53 54Face validity of FASH was assessed by three experts in content analysis procedure (step 3 of development), the participants who appraised the extent to which the instrument assessed their condition after completion of the questionnaire and the authors
 Content validity53 64The items of the FASH questionnaire were tested through a structured content-analytic method by 10 judges (step 4 of the development-item-content relevance analysis)
 Concurrent validity64 65Concerning FASH, a criterion scale does not exist; instead, the VISA-H58 59 was the only disease-related scale available for Greek-speaking patients (adapted, not published) whom we expected to correspond with the FASH. The patients during the initial assessment and before the administration of FASH were asked to complete the VISA-H questionnaire
 Factorial validity64 65The internal consistency of FASH was examined with exploratory principal component analysis in order to establish whether the items in the questionnaire group together in a consistent and clear manner
 Known group validity64 65Known group validity was tested by comparing the total FASH score of the participants’ groups. HMI group; other than HMI group; and healthy/at risk groups of patients are distinct subgroups that are expected to score differently in FASH
Reliability testing
 Inter-item reliability64 65Inter-item reliability of FASH was assessed by using coefficient α, which is considered to be the most proper way to estimate the internal consistency and structural validity of the subscales of the instrument
 Test–retest reliability65 66To evaluate the temporal stability, the scale was administered to all participants (N=140) twice
Feasibility and acceptability64To appraise the acceptability and the ease of administration of the FASH we recorded the time spent by participants filling it out and the percentage of unanswered questions
Ceiling and floor effects64 67The FASH would be considered to have ceiling and floor effects if more than 15% of the patients scored the maximum and minimum possible score, respectively. Relative to each item of the questionnaire, ceiling and floor effects were considered to have occurred if at least 75% of the patients scored the maximum or minimum score to that item, respectively
Responsiveness64To assess responsiveness, the FASH was administered only to the HMI group participants after they had completed their rehabilitation and before return to play (1–10 weeks). All athletes received the same standardised rehabilitation programme, which is described elsewhere.4 68 69 Return to full-sporting activities was determined by objective criteria previously described.70
  • FASH, Functional Assessment Scale for Acute Hamstring Injuries; HMI, hamstring muscle injuries; VISA, Victorian Institute of Sport Assessment questionnaire.