Clinical Orthopaedics and Related Research®

, Volume 472, Issue 3, pp 1010–1017

Association of a Modified Frailty Index With Mortality After Femoral Neck Fracture in Patients Aged 60 Years and Older

  • Kushal V. Patel
  • Kindyle L. Brennan
  • Michael L. Brennan
  • Daniel C. Jupiter
  • Adam Shar
  • Matthew L. Davis
Clinical Research

Abstract

Background

Frailty, a multidimensional syndrome entailing loss of energy, physical ability, cognition, and health, plays a significant role in elderly morbidity and mortality. No study has examined frailty in relation to mortality after femoral neck fractures in elderly patients.

Questions/purposes

We examined the association of a modified frailty index abbreviated from the Canadian Study of Health and Aging Frailty Index to 1- and 2-year mortality rates after a femoral neck fracture. Specifically we examined: (1) Is there an association of a modified frailty index with 1- and 2-year mortality rates in patients aged 60 years and older who sustain a low-energy femoral neck fracture? (2) Do the receiver operating characteristic (ROC) curves indicate that the modified frailty index can be a potential tool predictive of mortality and does a specific modified frailty index value demonstrate increased odds ratio for mortality? (3) Do any of the individual clinical deficits comprising the modified frailty index independently associate with mortality?

Methods

We retrospectively reviewed 697 low-energy femoral neck fractures in patients aged 60 years and older at our Level I trauma center from 2005 to 2009. A total of 218 (31%) patients with high-energy or pathologic fracture, postoperative complication including infection or revision surgery, fracture of the contralateral hip, or missing documented mobility status were excluded. The remaining 481 patients, with a mean age of 81.2 years, were included. Mortality data were obtained from a state vital statistics department using date of birth and Social Security numbers. Statistical analysis included unequal variance t-test, Pearson correlation of age and frailty, ROC curves and area under the curve, Hosmer-Lemeshow statistics, and logistic regression models.

Results

One-year mortality analysis found the mean modified frailty index was higher in patients who died (4.6 ± 1.8) than in those who lived (3.0 ± 2; p < 0.001), which was maintained in a 2-year mortality analysis (4.4 ± 1.8 versus 3.0 ± 2; p < 0.001). In ROC analysis, the area under the curve was 0.74 and 0.72 for 1- and 2-year mortality, respectively. Patients with a modified frailty index of 4 or greater had an odds ratio of 4.97 for 1-year mortality and an odds ratio of 4.01 for 2-year mortality as compared with patients with less than 4. Logistic regression models demonstrated that the clinical deficits of mobility, respiratory, renal, malignancy, thyroid, and impaired cognition were independently associated with 1- and 2-year mortality.

Conclusions

Patients aged 60 years and older sustaining a femoral neck fracture, with a higher modified frailty index, had increased 1- and 2-year mortality rates, and the ROC analysis suggests that this tool may be predictive of mortality. Patients with a modified frailty index of 4 or greater have increased risk for mortality at 1 and 2 years. Clinical deficits of mobility, respiratory, renal, malignancy, thyroid, and impaired cognition also may be independently associated with mortality. The modified frailty index may be a useful tool in predicting mortality, guiding patient and family expectations and elucidating implant/surgery choices. Further prospective studies are necessary to strengthen the predictive power of the index.

Level of Evidence

Level IV, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

References

  1. 1.
    Canadian Study of Health and Aging Working Group. Canadian study of health and aging: study methods and prevalence of dementia. CMAJ. 1994;150:899–913.Google Scholar
  2. 2.
    Chevalley T, Guilley E, Herrmann FR, Hoffmeyer P, Rapin CH, Rizzoli R. Incidence of hip fracture over a 10-year period (1991–2000): reversal of a secular trend. Bone. 2007;40:1284–1289.PubMedCrossRefGoogle Scholar
  3. 3.
    Christensen K, Doblhammer G, Rau R, Vaupel JW. Ageing populations: the challenges ahead. Lancet. 2009;374:1196–1208.PubMedCentralPubMedCrossRefGoogle Scholar
  4. 4.
    Endo Y, Aharonoff GB, Zuckerman JD, Egol KA, Koval KJ. Gender differences in patients with hip fracture: a greater risk of morbidity and mortality in men. J Orthop Trauma. 2005;19:29–35.PubMedCrossRefGoogle Scholar
  5. 5.
    Farhat JS, Velanovich V, Falvo AJ, Horst HM, Swartz A, Patton JH Jr, Rubinfeld IS. Are the frail destined to fail? Frailty index as a predictor of surgical morbidity and mortality in the elderly. J Trauma Acute Care Surg. 2012;72:1526–1530.PubMedCrossRefGoogle Scholar
  6. 6.
    Federal Interagency Forum on Aging-Related Statistics. Older Americans 2012: key indicators of well-being. 2010. Available at: http://www.agingstats.gov/agingstatsdotnet/main_site/default.aspx. Accessed July 24, 2013.
  7. 7.
    Freedman VA, Martin LG, Schoeni RF. Recent trends in disability and functioning among older adults in the United States: a systematic review. JAMA. 2002;288:3137–3146.PubMedCrossRefGoogle Scholar
  8. 8.
    Hu F, Jiang C, Shen J, Tang P, Wang Y. Preoperative predictors for mortality following hip fracture surgery: a systematic review and meta-analysis. Injury. 2012;43:676–685.PubMedCrossRefGoogle Scholar
  9. 9.
    Jaglal SB, Weller I, Mamdani M, Hawker G, Kreder H, Jaakkimainen L, Adachi JD. Population trends in BMD testing, treatment, and hip and wrist fracture rates: are the hip fracture projections wrong? J Bone Miner Res. 2005;20:898–905.PubMedCrossRefGoogle Scholar
  10. 10.
    Kannus P, Niemi S, Parkkari J, Palvanen M, Vuori I, Järvinen M. Nationwide decline in incidence of hip fracture. J Bone Miner Res. 2006;21:1836–1838.PubMedCrossRefGoogle Scholar
  11. 11.
    Kirkland LL, Kashiwagi DT, Burton MC, Cha S, Varkey P. The Charlson Comorbidity Index Score as a predictor of 30-day mortality after hip fracture surgery. Am J Med Qual. 2011;26:461–467.PubMedCrossRefGoogle Scholar
  12. 12.
    Lee DH, Buth KJ, Martin BJ, Yip AM, Hirsch GM. Frail patients are at increased risk for mortality and prolonged institutional care after cardiac surgery. Circulation. 2010;121:973–978.PubMedCrossRefGoogle Scholar
  13. 13.
    Makary MA, Segev DL, Pronovost PJ, Syin D, Bandeen-Roche K, Patel P, Takenaga R, Devgan L, Holzmueller CG, Tian J, Fried LP. Frailty as a predictor of surgical outcomes in older patients. J Am Coll Surg. 2010;210:901–908.PubMedCrossRefGoogle Scholar
  14. 14.
    Manton KG. Recent declines in chronic disability in the elderly U.S. population: risk factors and future dynamics. Annu Rev Public Health. 2008;29:91–113.PubMedCrossRefGoogle Scholar
  15. 15.
    Miller CW. Survival and ambulation following hip fracture. J Bone Joint Surg Am. 1978;60:930–934.PubMedGoogle Scholar
  16. 16.
    Mitnitski AB, Mogilner AJ, MacKnight C, Rockwood K. The mortality rate as a function of accumulated deficits in a frailty index. Mech Ageing Dev. 2002;123:1457–1460.PubMedCrossRefGoogle Scholar
  17. 17.
    Pilotto A, Rengo F, Marchionni N, Sancarlo D, Fontana A, Panza F, Ferrucci L; FIRISIGG Study Group. Comparing the prognostic accuracy for all-cause mortality of frailty instruments: a multicentre 1-year follow-up in hospitalized older patients. PLoS One. 2012;7:e29090.PubMedCentralPubMedCrossRefGoogle Scholar
  18. 18.
    Rockwood K, Song X, MacKnight C, Bergman H, Hogan DB, McDowell I, Mitnitski A. A global clinical measure of fitness and frailty in elderly people. CMAJ. 2005;173:489–495.PubMedCentralPubMedCrossRefGoogle Scholar
  19. 19.
    Rockwood K, Song X, Mitnitski A. Changes in relative fitness and frailty across the adult lifespan: evidence from the Canadian National Population Health Survey. CMAJ. 2011;183:E487–E494.PubMedCentralPubMedCrossRefGoogle Scholar
  20. 20.
    Rockwood K, Stadnyk K, MacKnight C, McDowell I, Hébert R, Hogan DB. A brief clinical instrument to classify frailty in elderly people. Lancet. 1999;353:205–206.PubMedCrossRefGoogle Scholar
  21. 21.
    Söderqvist A, Ekström W, Ponzer S, Pettersson H, Cederholm T, Dalén N, Hedström M, Tidermark J; Stockholm Hip Fracture Group. Prediction of mortality in elderly patients with hip fractures: a two-year prospective study of 1,944 patients. Gerontology. 2009;55:496–504.PubMedCrossRefGoogle Scholar
  22. 22.
    Souza RC, Pinheiro RS, Coeli CM, Camargo KR Jr. The Charlson comorbidity index (CCI) for adjustment of hip fracture mortality in the elderly: analysis of the importance of recording secondary diagnoses. Cad Saude Publica. 2008;24:315–322.PubMedGoogle Scholar
  23. 23.
    Stevens JA, Anne Rudd R. Declining hip fracture rates in the United States. Age Ageing. 2010;39:500–503.PubMedCrossRefGoogle Scholar
  24. 24.
    US Department of Health and Human Services. Administration on Aging. A profile of older Americans 2010: key indicators of well-being. Available at: http://www.aoa.gov/aoaroot/aging_statistics/profile/2010/docs/2010profile.pdf. Accessed December 10, 2012.
  25. 25.
    World Population Ageing 2009. Department of Economic and Social Affairs of the United Nations Population Division. Available at: http://www.un.org/en/development/desa/publications/world-population-ageing-2009.html. Accessed July 24, 2013.

Copyright information

© The Association of Bone and Joint Surgeons® 2013

Authors and Affiliations

  • Kushal V. Patel
    • 1
  • Kindyle L. Brennan
    • 1
  • Michael L. Brennan
    • 1
  • Daniel C. Jupiter
    • 2
  • Adam Shar
    • 1
  • Matthew L. Davis
    • 2
  1. 1.Department of OrthopaedicsScott and White Memorial HospitalTempleUSA
  2. 2.Department of SurgeryScott and White Memorial HospitalTempleUSA

Personalised recommendations