Questionnaire is available here in html format.
A pdf version of the sf36 is also available
here, for ease of administration (it fits on 2 pages!).
Devised
by:
John E. Ware Jr. PhD – QualityMetric, Inc. Address:
640 George Washington Hwy, Suite 201, RI. Phone 401 334 8800, x242, Fax: 401 334
8801, email: jware@qmetric.com. Internet
site www.sf36.com.
Research
supported by:
The Henry J. Kaiser Family Foundation, Menlo Park,
CA (Grant no. 85-6515) granted to the Health Institute, New England Medical
Center.
Co-copyright
Holders:
Medical Outcome Trust (MOT), Health Assessment
Laboratories (HAL) and QualityMetric Incorporated.
Licensing:
Fee for use of the SF- 36™ is paid by companies
and organisations who will profit from the use of the instrument. This allows
the MOT, HAL and QualityMetric Inc “to make surveys available royalty free to
individuals and organisations for academic research”.
The SF-36™ is distributed by MOS Trust Inc and
“strict adherence to item wording and scoring recommendations is required in
order to use the SF-36 trademark” www.sf-36.com.
The SF- 36™ is a short form measure of generic
health status in the general population. The SF-36™ is designed for
self-administration. Alternatively, a trained interviewer can use a standardized
script for face to face and telephone interview. The SF™-36 takes 5 –10
minutes for respondent to complete. Can be administered to anyone over the age
of 14. www.qualitymetric.com/innohome/insf36.shtml
From
the 36 items, eight health profiles are derived from summarised scores. All
dimensions are independent of each other. A comprehensive manual and
interpretation guide is available from the author (Ware, 1993).
www.qualitymetric.com/innohome/insf36.shtml.
The SF-36 has been translated and adapted in 29
countries. It has been translated into languages including: English, Spanish,
French, Swedish, Korean, German, Dutch, Portuguese, Chinese, Czech, Finnish,
Danish, Hungarian, Hebrew, Italian, Japanese, Norwegian, Polish, Romanian,
Slovak, Russian, Afrikaans. Furthermore, the SF-36 has been replicated across 24
different patient groups from various socio-economic situations and diagnosis
(Ware, J, 1996). From an Australian and particularly Melbourne perspective this
instrument has great utility in a multicultural city providing predominantly
Anglo-Saxon services.
One study found that the SF-36 yielded a high rate
of response (83%) and rate of completion (95%) (Brazier, Harper, Jones,
O’Cathain, Thomas, et al, 1992). A study consisting of 19,785 respondents over
18 years of age yielded an 80.6% full completion of SF-36 and 14.6% partial
completion (The Australian Bureau of Statistics (ABS), 1995). Using Cronbach’s
alpha, an alpha of 0.5 is acceptable, Nunnally recommends 0.7 and above.
Well-used tests should give 0.8 and above (Jenkinson et al, 1993, p.4).
Cronbach's alpha on all scales of the SF-36 exceed alpha of 0.8, except for
social functioning (α
= 0.76) (Jenkinson et al, 1993). Similar findings have been reported by Brazier,
Harper and Jones et al (1992). In
the case of the Social Functioning dimension the results are considered
acceptable due to the small number of items (2 items using a 5 point scale;
Jenkinson et al, 1993). The Physical Functioning dimension has consistently
exceeded 0.90 (Ware, 1993).
The 8 Health Profiles including number of items, Cronbach’s alpha and item internal consistency.
|
Scale |
Number
of items |
Definition of scale |
Internal consistency reliability (Cronbach’s alpha) |
Range
of item internal consistency |
|
Physical
Functioning – (PF) |
10
items |
Limitations
in physical activity because of health problems |
α= 0.93 |
0.64
– 0.83 |
|
Social
Functioning (SF)
|
2
items |
Limitations
in social activities because of physical or emotional problems |
α = 0.90 |
0.39-0.56 |
|
Role
limitations – physical (RP) |
4
items |
Limitations
in usual role activities because of physical health problem |
α = 0.82 |
0.86-0.89 |
|
Bodily
pain (BP) |
2
items |
Presence
of pain and limitations due to pain |
α = 0.95 |
0.26-0.56 |
|
General
medical health (GH) |
5
items |
Self
evaluation of personal health |
α = 0.82 |
0.65-0.83 |
|
Mental
health (MH) |
5
items |
Psychological
distress and well-being. |
α = 0.80 |
0.62
–0.77 |
|
Role
limitations – emotional (RE) |
3
items |
Limitations
in usual role activities because of emotional problems. |
α = 0.83 |
0.83
–0.77 |
|
Vitality
(VT) |
4
items |
Energy
and fatigue |
α =0.82 |
0.77
–0.80 |
|
General
Health perceptions |
Single
item |
|
|
|
|
Scott,
Tobias , Sarfati & Haslett (1999). |
||||
Additionally two composite summary scores measure
physical health and mental health (Ware, J. E. 1992). Reliability estimates for
the composite physical and mental summary scores usually exceed 0.90.
Brazier, Harper and Jones (1992) used the Bland and
Altmann technique.
‘The
differences [in scores] are plotted, an overall mean and variance of differences
calculated, and 95% confidence intervals constructed around the mean by assuming
a normal distribution. The test and retest scores are assumed to be from the
same distribution when the differences have a mean of zero and 95% of the
differences lie within the 95% confidence limits’ (Brazier, Harper &
Jones, 1992, p161).
The researchers found for all dimensions 91-98% of
cases lay within the 95% confidence interval. The maximum mean difference in
dimension scores was 0.80.
The SF-36 is available in standard version when
post-test occurs at 4 weeks. The acute version is available when time
limitations require a one-week recall. (McDowell & Newell, 1996)
The SF-36 is acceptable to patients (Brazier et al,
In Jenkinson et al, 1993), and has practical advantages over such instruments as
Sickness Impact Profile, in that it is shorter, and the Nottingham Profile,
which has been found to be insensitive to lower levels of dysfunction and
disability (Jenkinson et al, 1993).
The SF-12 and SF-8 health survey are also available
from the author. The SF-36 and SF12
now have version 2 options. The SF-36 provides greater precision than the SF-12
by providing more detailed information in physical and mental scales, and more
robust assessment of the 8 scales. However, it takes longer to complete when
compared to the SF 8 (1-2 minutes), and the SF-12 (2 – 3 minutes) and printing
space becomes incrementally larger.
www.sf-36.com/faq/generalinfo.shtml#1105.
Some variability in data completeness has been
found across population sub-groups in a New Zealand study. This was particular
to the elderly and Pacific people. (Scott, Tobias, Sarfati Haslett, 1999). In an
Australian sample question 9i and 3c had the highest levels of missing data
respectively.
Criterion validity is presented in the SF-36 manual
for all dimensions except vitality and social functioning. Each scale reportedly
provides a valid representation of the criterion to be measured (Ware, 1993).
The SF-36 has been linked to utilization of health care services, clinical
course of depression and five-year survival (Ware, J. E 1996). Question items
contributing to each dimension are appropriate.
The test items are representative of the conceptual
domains of Physical Functioning, General Health and Vitality (Ware, 1993). The
author reports that content validity compares favourably with other widely used
generic health surveys (Ware, J 1996). The content validity is further supported
by the work of Brazier, Harper & Jones, 1992).
Both physical and mental health scale scores
decline in a predictable manner across the 8 scales (Anderson, 1996). The eight
scales and 2 summary scales diverge as expected.
In a psychometric and clinical test of validity,
the following Rotated Principle Components and relative validity yielded strong
association (r ≥ 0.70) for Physical health: Physical functioning (RPC
= 0.88, RV = 1.00), Role- physical (RPC = 0.78, RV = 0.79), and Bodily pain (RPC
= 0.77, RV = 0.77). Mental health: Mental health (RPC = 0.90, RV = 1.00), role
– emotional (RPC = 0.81, RV = 0.81), and Social functioning (RPC = 0.71, RV =
0.62) (McHorney, Ware & Raczek (1993). Construct validity was also supported
by a New Zealand study (Scott, Tobias, Sarfati, & Haslett, 1999).
Evidence of construct validity is acceptable on
variables of age, gender, socio-economic class, (Jenkinson, et al 1993) presence
or absence of chronic physical problems and recent consultation with general
practitioner (2 weeks) or outpatient service (3 months) (Brazier et al, 1992).
|
Physical
functioning |
0.15
–0.56 |
Vitality |
0.24
–1.52 |
|
Role
physical |
0.20
– 0.58 |
Social
Functioning |
0.39
–0.56 |
|
Bodily
pain |
0.26
–0.56 |
Role
emotional |
0.24
–0.52 |
|
General
health |
0.19
–0.56 |
Mental
Health |
0.10
–0.55 |
|
Scott,
Tobias Sarfati and Haslett (1999) found good item discriminant validity.
The lower the correlation the better the discriminant validity. |
|||
McHorney, Ware & Raczek (1996) analysed the
validity of the physical and mental health constructs. These results show
clearly the convergent and discriminant validity of the SF 36. The SF-36 can
discriminate between mental health and physical health among medical and
psychiatric patients.
Role physical and role emotional showed strong
convergent and discriminant validity, Social function scale showed moderate to
strong convergent and discriminant validity, Vitality showed good convergent
validity but poor discriminant validity. General health perception showed good
convergent validity for physical health but poor convergent validity for mental
health. Bodily pain showed strong convergent validity in physical health and
poor convergent in medical severity clinical test. The authors suggest that the
result for bodily pain is most likely a research artefact, as the medical
conditions used in the study were not dominated by pain (McHorney et al, 1993).
Overall the scales contained within the SF-36 are
sensitive to clinical manifestations of medical (physical functioning) and
global psychiatric (mental health) conditions. It is sensitive to mild
functional losses relevant to independent living (Anderson, 1996) and ‘can
detect higher levels of everyday physical functioning allowing a broader range
of needs to be identified’ (Anderson, 1996, p6). The SF- 36 is able to detect
low levels of ill health (Brazier, 1992). This instrument is sensitive to change
and therefore can be used for pre and post measurement. However, the psychiatric
aspects of this questionnaire are quite medically biased.
www.sf-36.com/faq/generalinfo.shtml#1105
Web based scoring is an option and takes about five
minutes to complete the questionnaire and receive results and composite scores.
On-line demonstration and scoring are available www.sf-36.com.
The manual comprehensively outlines scoring and
includes methods of item recoding, recalibration, treatment of missing data,
computing raw scores, and transformation of scores. To access the manual,
contact the authors www.sf-36.com.
Scores for all dimensions are expressed on a scale
0-100, where higher scores indicate better health and well-being.
NBS of SF-36 are based on general US populations.
Scores can be transformed to
make a minimum and maximum possible score of between 0 and 100.
All scores above or below 50 can be interpreted as above or below the
general population norm and because the standard deviation for each scale is
equalized at 10, it is easy to see exactly how far above (or below) the average
score any result is in standard deviation units.
A score of 1.96 standard deviations (»20) above or below the mean would
suggest that, with 95% confidence, the sample is healthier or unhealthier than
are people in general on that measure.
Under such norm-based scoring, the following
occurs:
The items are scored and entered;
The items requiring it are recoded;
Scale scores are computed by summing across the
recoded items under each scale;
The scale scores are transformed (to make them out
of 0 to 100);
An algorithm is applied to make the scores
relational to some aspect of the population (e.g. Males) whereby a score of
50 is the mean and 10 is the standard deviation.
However, because there is not always a readily
available algorithm to make the scores comparative to some aspect of the
population you want to look at (e.g., males, or 55-64 year age group, or
smokers, or even male 55-64 years old who smoke, etc), step 5 is not always
followed. In these cases a score above 50 can be interpreted as being
representative of having
a more positive response set to whatever that scale measures (e.g.
vitality) rather than worse. However,
this does not translate to population means (i.e.
a score of above 50 does not mean that the veteran is doing better than
the general population on this scale, and a score of below 50 does not mean that
the veteran is worse than the average male of equal age in the community). To allow for such a comparison one must obtain norm scores
for the comparison group from another study or organisation (e.g. Australian
Bureau of Statistics).
www.qualitymetric.com/innohome/norm.shtml.
Lower scores on the SF-36 reflect poorer health,
long-standing illness, medical consultation in the past 2 weeks, and women
generally reflect poorer scores on all variables (Jenkinson et al, 1993).
This also means that scores from the original SF-36
can be compared to scores from SF-36 Version 2.
Australian norms for the SF-36 have not
standardised the eight scales to a mean of 50. However the Physical and mental
component scores do have a mean of 50 and standard deviation of 10.
Amongst other population samples, the SF-36 has
been used to compare quality of life and:
|
Breast
cancer |
Schizophrenia |
Sleep
apnoea |
|
Radiation
and cancer |
Mood
and anxiety disorders |
Non
surgical patients with lower extremity peripheral artery disease |
|
Pulmonary
function |
Negative
affect |
Chronic
heart disease |
|
Haemodialysis
and peritoneal dialysis |
Depressive
symptoms in asthmatic patients |
Epilepsy
and seizure frequency |
|
Carpal
tunnel syndrome |
Solid
organ transplant |
Pulmonary
rehabilitation |
In the case where a researcher is using other
instruments concurrent to the SF-36, the SF-36 should be presented first.
www.sf-36.com/faq/generalinfo.shtml#1105
Contains no variable for sleep.
Lower response rate for the >65 population
therefore researchers might consider using an alternative questionnaire.
Bell, Kahn et al used the SF-36 to assess health
status via the web. Participants remained anonymous. Item inter-correlation of
99.28% was found. Cronbach’s alpha was in an acceptable range (0.76 to 0.90).
Australian Bureau of Statistics (1995). National
Health Survey: SF-36 Population Norms. 4399.0
Anderson, C., Laubscher, S., & Burns, R (1996).
Validation of the short form 36 (SF-36) health survey questionnaire among stroke
patients. Stroke 27 (10), 1812 –1816.
Bell, D. S., Kahn C. E (Jr) (1996). Assessing
health status via the World Wide Web. In Cimino JC, (Ed) Proceeding of the AMIA
Annual Fall Symposium. Philadelphia: Hanley & Belfus 338-342. (Abstract
only)
Brazier, J. E., Harper, R., Jones, N.M.B.,
O’Cathain, A., Usherwood, T., & Westlake, J. (1992) Validating the SF-36
Health survey questionnaire: new outcome measure for primary care. British
Medical Journal, 305, 160- 164
Jenkinson, C., Coulter, A., & Wright, L (1993).
Short Form 36 (SF-36 health survey questionnaire: Normative data for adults of
working age. British Medical Journal, 306 (6890), 1437-1440.
McHorney, C. A., Ware, J. E (Jr)., & Raczek, A.
E. (1993) The MOS 36-Item short form health survey (SF-36): II. Psychometric and
Clinical Tests of validity in measuring physical and mental health constructs.
Medical Care. 31 (3) 247-263.
Scott, K. M., Tobias, M. I., Sarfati, D., &
Haslett, S (1999). SF-36 health survey reliability, validity and norms for New
Zealand. Australian and New Zealand Journal of Public Health. 23,
401-406.
Ware, J. E, (1993). SF-36 Health Survey: Manual and
Interpretation Guide. Boston: The Health Institute, New England Medical Center.
Ware, J. E, (1996). The MOS 36-Item Short Form
Health Survey (SF-36). In Sederer, L. I & Dickey, B (1996). Outcomes Assessment in Clinical Practice. Baltimore: Williams
and Wilkins.
Ware, J. E and Sherbourne C. D (1992). The MOS
36-item short form health survey (SF-36.) I. Conceptual framework and item
selection Medical Care 30, 473-483.
Above written by: Ms. Lisa Pearson
Reviewed, edited and approved by: Dr. Grant J. Devilly