Effects of 16-week Tai Chi intervention on postural stability and proprioception of knee and ankle in older people

1. Van den Akker M, Buntinx F, Metsemakers JF et al. Multimorbidity in general practice: prevalence, incidence, and determinants of co-occurring chronic and recurrent diseases. J Clin Epidemiol 1998; 51: 367–75. 2. Fortin M, Bravo G, Hudon C et al. Prevalence of multimorbidity among adults seen in family practice. Ann Fam Med 2005; 3: 223–8. 3. Gijsen R, Hoeymans N, Schellevis FG et al. Causes and consequences of comorbidity: a review. J Clin Epidemiol 2001; 54: 661–74. 4. Starfield B, Lemke KW, Herbert R et al. Comorbidity and the use of primary care and specialist care in the elderly. Ann Fam Med 2005; 3: 215–22. 5. Department of Health. National Service Framework for Older People (2001). www.dh. gov.uk (accessed 10 January 2007). 6. Department of Health. The NHS Plan: a plan for investment, a plan for reform (2000). www.dh. gov.uk (accessed 10 January 2007). 7. Jordan K, Ong BN, Croft P. Previous consultation and self reported health status as predictors of future demand for primary care. J Epidemiol Community Health 2003; 57: 109–13. 8. Porcheret M, Hughes R, Evans D et al. Data quality of general practice electronic health records: the impact of a program of assessments, feedback, and training. J Am Med Inform Assoc 2004; 11: 78–86. 9. Jordan K, Clarke AM, Symmons DPM et al. Measuring disease prevalence: a comparison of musculoskeletal disease using four general practice consultation databases. Br J Gen Pract 2007; 57: 7–14. 10. Office of National Statistics. England and Wales; estimated resident population by single year of age and sex; Mid-2004 Population, www.statistics. gov.uk/statbase/ssdataset.asp? vlnk=9084 &More=Y (accessed 28 June 2007). 11. Fleming DM, Cross KW, Barley MA. Recent changes in the prevalence of diseases presenting for health care. Br J Gen Pract 2005; 55: 589–95. 12. Hippisley-Cox J, Pringle M, Cater R et al. Coronary heart disease prevention and age inequalities: the first year of the National Service Framework for CHD. Br J Gen Pract 2005; 55: 369–75. 13. Rothwell PM, Coull AJ, Giles MF et al. Change in stroke incidence, mortality, case-fatality, severity, and risk factors in Oxfordshire, UK from 1981 to 2004 (Oxford Vascular Study). Lancet 2004; 363: 1925–33. 14. Office of National Statistics. Key Health Statistics for General Practice. London: National Statistics, 1998. 15. Smith G, Smith S, Heatlie H et al. What has happened to antimicrobial usage in primary care in the United Kingdom since the SMAC report? Description of trends in antimicrobial usage using the General Practice Research Database. J Public Health 2004; 26: 359–64. 16. Ashworth M, Charlton J, Ballard K et al. Variations in antibiotic prescribing and consultation rates for acute respiratory infection in UK general practices 1995–2000. Br J Gen Pract 2005; 55: 603–8. 17. Freeman GK, Horder JP, Howie JG et al. Evolving general practice consultation in Britain: issues of length and context. BMJ 2002; 324: 880–2. 18. Boyd CM, Darer J, Boult C et al. Clinical practice guidelines and quality of care for older patients with multiple comorbid diseases: implications for pay for performance. JAMA 2005; 294: 716–24. 19. Starfield B. Threads and yarns: weaving the tapestry of comorbidity. Ann Fam Med 2006; 4: 101–3.