What is new?
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This study provides Medical Outcomes Study 36-Item Short Form Version 2 (SF-36v2) telephone-administered norms for the 2005–2006 US general population aged 35–89 years.
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The 2005–2006 SF-36v2 scores are higher than the 1998 norms, which are likely due to telephone administration.
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The 2005–2006 norms can be used to help interpret SF-36v2 scale and component summary scores.
The Medical Outcomes Study 36-Item Short Form Version 2 (SF-36v2; QualityMetric, Lincoln, RI) is one of the most commonly used generic health-related quality of life (HRQOL) instruments. The SF-36v2 was derived from 40 concepts captured in the Medical Outcomes Study [1], [2]. It is composed of eight multi-item scales: physical functioning, role limitations due to physical health, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health. Additionally, the scores from the SF-36v2 scales can be combined into physical and mental component summary (PCS and MCS) scores [3].
The first version of the SF-36 was made available in 1990 [4]. Based on work in the International Quality of Life Assessment project [5] and the Veterans Health Survey [6], item wording and response categories were refined to create the SF-36v2. The SF-36v2 uses norm-based scoring in which the scale and component summary scores have a mean of 50 and standard deviation of 10 in the US general population. Norms were derived from the 1998 National Survey of Functional Health Status sample of respondents that was designed, based on geographical region, market size, age, income, and household size, to be representative of the noninstitutionalized adult US population [5]. The 1998 SF-36v2 US general population norms have allowed for comparisons of scores from groups with different demographic characteristics or different health conditions.
Standard scoring of the PCS and MCS is based on factor score coefficients or weights from each scale of the SF-36v2 obtained from principal component analysis with orthogonal rotation (i.e., uncorrelated factors) [7]. Alternatively, physical and mental component summaries can be viewed as correlated. Physical and mental health summary scores derived from obliquely rotated factor solutions have also been derived for the SF-36v1 [8], [9].
Norms for the SF-36v2 have not been updated since 1998. However, the median age and proportion of minorities have increased in the US population since then [10]. Furthermore, the prevalence of obesity has increased among men from 1999 to 2004 [11], whereas age-adjusted mortality from cardiovascular disease has declined [12]. In order for scale and component summary score comparisons to be more current and relevant, the SF-36v2 norms need updating.
Over a 13-month period in 2005–2006, a cross-sectional survey of 3,844 US adults was conducted in the National Health Measurement Study (NHMS). Several generic HRQOL were administered, including the SF-36v2. In this study, we report new US norms for the eight scales of the SF-36v2, and the PCS and MCS. We provide both orthogonal and oblique factor score coefficients.