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QUALITY OF LIFE IN HYPERTENSION, SF-36
The SF-36 has frequently been used to measure health related quality of life (HRQOL) in hypertension. Recently, the SF-12, a shorter form of the SF-36, has been proposed. However, the validity of the SF-12 in hypertension has not yet been assessed.
To determine the extent to which the SF-12 provides similar measurements of HRQOL to those of the SF-36 in hypertensive individuals.
A study assessing the impact of a pharmacy-based intervention program on hypertensive individuals served as background for this study. One hundred and twelve individuals participated in this study. We compared the SF-36 with the SF-12 on item scores and summary measures using intraclass correlation coefficients (ICC), Pearson’s correlation coefficients and linear regression.
The concordance between the SF-12 and the SF-36 on both physical (ICC=0.88) and mental (ICC=0.92) component summary scores (PCS and MCS respectively) is high and the relationship is linear and positive. Most of the variance in the SF-36 PCS (R2=0.78) and MCS (R2=0.85) can be explained by their SF-12 counterparts. The SF-12 PCS and MCS are the only significant predictor variables for the corresponding measure of the SF-36.
The SF-12 appears to be a valid alternative to the SF-36 for clinical practice or research purposes when studying hypertensive individuals and their treatment.
2. Testa MA and Simonson DC. Assessment of quality-of-life outcomes. N Engl J Med 1996; 334:835-840.
3. Lawrence WF, Fryback DG, Martin PA, et al.Health status and hypertension: A population- based study. J Clin Epidemiol 1996; 49: 1239-1245.
4. Fletcher AE, Chester PC, Hawkins CM, et al. The effects of verapamil and propranolol on quality of life in hypertension. J Hum Hypertens 1989; 3:125-130.
5. Hill JF, Bulpitt CJ and Fletcher AE. Angiotensin converting enzyme inhibitors and quality of life: the European trial. J Hypertens Suppl 1985; 3:S91-94.
6. Stewart AL, Hays RD and Ware JE. The MOS short-form general health survey. Med Care 1988; 26: 724-738.
7. Côté I, Grégoire JP and Moisan J. Health-related quality of life measurement in hypertension. A review of randomised controlled drug trials. Pharmacoeconomics 2000; 18: 435-450.
8. McHorney CA, Ware JE, Jr., Lu JFR, et al. The MOS 36-items Short-form Health Survey (SF-36): III: Tests of data quality, scaling assumptions, and reliability across diverse patient groups. Med Care 1994; 32: 40-63.
9. Ware JE, Jr., Kosinski M and Keller SD. A 12- items short-form health survey. Med Care 1996; 34: 220-233.
10. Pickard AS, Johnson JA, Penn A, et al.Replicability of SF-36 summary scores by the SF-12 in stroke patients. Stroke 1999; 30: 1213-1217.
11. Côté I, Grégoire JP, Moisan J, et al. A pharmacy- based health promotion programme in hypertension: cost-benefit analysis. Pharmacoeconomics 2003; 21: 415-428.
12. Dauphinee S, Gauthier L, Gandek B, et al. Readying a US measure of health status, the SF-36, for use in Canada. Clin Invest Med 1997; 20: 224-
13. Ware J, Snow K, Kosinski M, et al. SF-36 Health Survey Manual and Interpretation Guide. Boston, Mass: The Health Institute, New England Medical Center; 1993.
14. Samsa G, Edelman D, Rothman ML, et al. Determining clinically important differences in health status measures: a general approach with illustration to the Health Utilities Index Mark II. Pharmacoeconomics 1999; 15: 141-155.
15. Gandek B, Ware JE, Aaronson NK, et al. Cross- validation of item selection and scoring for the SF-12 Health Survey in nine countries: results from the IQOLA Project. International Quality of Life Assessment. J Clin Epidemiol 1998; 51: 1171-1178.
16. Lim LL and Fisher JD. Use of the 12-item short- form (SF-12) Health Survey in an Australian heart and stroke population. Qual Life Res 1999; 8: 1-8.
17. Bulpitt CJ and Fletcher AE. The measurement of quality of life in hypertensive patients: a practical approach. Br J Clin Pharmacol 1990; 30: 353-364.