GameBus Pilot Studies (5): Internal Consistency Reliability - Chronbach's Alpha

Internal consistency reliability estimates (Cronbach’s coefficient alpha) for the eight SF-36v2 scales for pre- and post-test of both pilot locations.Most health dimension scales exceed the recommended 0.70, while others score excellent with close to or over 0.90.<br>** However, we do have to mention that two scales - BP and SF - exist of two items in SF36v2 that measure said constructs and do not provide a proper alpha value for the post-tests of Trial A and Trial B respectively . For these, a negative alpha is determined. Although theoretically, this should not be possible, we are sure that all (if needed) items are re-coded in SPSS &amp; the 'QualityMetric Health Outcomes Scoring Software 4.5’ software package and no other issues exist, before actually calculating the alpha values. This has also been confirmed by the SF-36 Guide Book, section 2.3: p.11 (Zee &amp; Sanderman, 2012). **<br>Zee, K. I. Van Der, &amp; Sanderman, R. (2012). Het meten van de algemene gezondheidstoestand met de RAND-36. Een handleiding. Groningen.