One-Year Readmission Risk and Mortality after Hip Fracture Surgery: A National Population-Based Study in Taiwan
Lee Tien-Ching1,2,8, Ho Pei-Shan4, Lin Hui-Tzu5, Ho Mei-Ling1,6,7, Huang Hsuan-Ti3,7, Chang Je-Ken1,3,7,*
1Orthopaedic Research Center, College of Medicine, Kaohsiung Medical University Hospital 2Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University Hospital 3Department of Orthopaedics, Kaohsiung Medical University Hospital 4Faculty of Dental Hygiene, College of Dental Medicine 5Center of Teaching and Research, Kaohsiung Municipal Ta-Tung Hospital 6Department of Physiology, College of Medicine 7Department of Orthopaedics, College of Medicine, Kaohsiung Medical University Hospital 8Department of Orthopedics, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
Early readmission following hip fracture (HFx) is associated with high morbidity and mortality. We conducted a survival analysis of patients with readmission within 1 year after HFx to elucidate the trend and predictors for readmission. We used Taiwan National Health Insurance Database to recruit HFx patients who underwent operations between 2000 and 2009. Patients < 60 years; with pathological fractures; involved in major traffic accidents; with previous pelvis, femur, and hip operations; or who died during the index admission were excluded. We used the Chi-square test, logistic regression, Kaplan-Meier method, and Cox proportional hazards model to analyze variables, including age, gender, hospital stay duration, index admission time, and comorbidity on readmission. 5,442 subjects (61.2% female) met the criteria with mean age of 78.8 years. Approximately 15% and 43% HFx patients were readmitted within 30 days (early) and between 30 days and 1 year (late) after discharge, respectively. Highest readmission incidence was observed within the first 30 days. Most common causes of readmission in early and late groups were respiratory system diseases and injuries, respectively. Cox model showed male, old age, hospital stay > 9 days, Charlson Comorbidity Index ≥ 1, index admission during 2000–2003, and internal fixation of HFx were independent predictors of readmission. One-year mortality of the early and the late readmission groups was 44.9% and 32.3%, much higher than overall mortality which was 16.8%. Predictive factors for readmission within 1 year included male, old age, comorbidities, and longer hospital stay. One-year mortality in readmitted patients was significantly higher. HFx patients with these factors need careful follow-up, especially within 30 days after discharge.
Lee Tien-Ching,Ho Pei-Shan,Lin Hui-Tzu, et al. One-Year Readmission Risk and Mortality after Hip Fracture Surgery: A National Population-Based Study in Taiwan[J]. Aging and disease,
2017, 8(4): 402-409.
Table 1 Demographics of Early and Late Readmission Groups.
Time of admission
Table 2 Cox Proportional Hazards Regression Model of Early and Late Readmission Groups.
Figure 1. Kaplan-Meier curve showing the time to readmission over the first year following initial discharge after operation for hip fractures
A) Kaplan-Meier curves by gender (M: male; F: female). B) Kaplan-Meier curves by age. C) Kaplan-Meier curves by the three-study periods of index admission for hip fractures. D) Kaplan-Meier curves by the length of hospital stay. E) Kaplan-Meier curves by Charlson Comorbidity Index (CCI). F) Kaplan-Meier curves by operation type (Art: Arthroplasty; Fix: Internal fixation).
Figure 2. Distribution of readmission causes in different time periods within 1 year using International Classification of Diseases, Version 9, Clinical Modification (ICD-9-CM) coding
001-139: Infectious and parasitic diseases; 140-239: Neoplasms; 240-279: Endocrine, nutritional and metabolic diseases, and immunity disorders; 280-289: Diseases of the blood and blood-forming organs; 290-319: Mental disorders; 320-389: Diseases of the nervous system and sense organs; 390-459: Diseases of the circulatory system; 460-519: Diseases of the respiratory system; 520-579: Diseases of the digestive system; 580-629: Diseases of the genitourinary system; 630-679: Complications of pregnancy, childbirth, and the puerperium; 680-709: Diseases of the skin and subcutaneous tissue; 710-739: Diseases of the musculoskeletal system and connective tissue; 740-759: Congenital anomalies;760-779: Certain conditions originating in the perinatal period.
Time of readmission
Mortality within one year
Table 3 One-year mortality rate at different time of readmission.
Cooper C, Campion G, Melton LJIII, (1992). Hip fractures in the elderly: a world-wide projection. Osteoporos Int, 2: 285-289.
Wang CB, Lin CF, Liang WM, Cheng CF, Chang YJ, Wu HC,et al. (2013). Excess mortality after hip fracture among the elderly in Taiwan: a nationwide population-based cohort study. Bone, 56: 147-153.
Abrahamsen B, van ST, Ariely R, Olson M, Cooper C (2009). Excess mortality following hip fracture: a systematic epidemiological review. Osteoporos Int, 20: 1633-1650.
Forsen L, Sogaard AJ, Meyer HE, Edna T, Kopjar B (1999). Survival after hip fracture: short- and long-term excess mortality according to age and gender. Osteoporos Int, 10: 73-78.
Johnell O, Kanis JA (2004). An estimate of the worldwide prevalence, mortality and disability associated with hip fracture. Osteoporos Int, 15: 897-902.
Magaziner J, Lydick E, Hawkes W, Fox KM, Zimmerman SI, Epstein RS,et al. (1997). Excess mortality attributable to hip fracture in white women aged 70 years and older. Am J Public Health, 87: 1630-1636.
Vestergaard P, Rejnmark L, Mosekilde L (2007). Increased mortality in patients with a hip fracture-effect of pre-morbid conditions and post-fracture complications. Osteoporos Int, 18: 1583-1593.
Wolinsky FD, Fitzgerald JF, Stump TE (1997). The effect of hip fracture on mortality, hospitalization, and functional status: a prospective study. Am J Public Health, 87: 398-403.
Shao CJ, Hsieh YH, Tsai CH, Lai KA (2009). A nationwide seven-year trend of hip fractures in the elderly population of Taiwan. Bone, 44: 125-129.
Ministry of Interior (2012). 2011 Demographic Fact Book Republic of China. Ministry of Interior, Taipei, Taiwan.
Council for Economic Planning and Development (2012). National population estimate from 2012 to 2060 [in Chinese], Executive Yuan, Taipei, Taiwan.
Benbassat J, Taragin M (2000). Hospital readmissions as a measure of quality of health care: advantages and limitations. Arch Intern Med, 160: 1074-1081.
Morris MS, Deierhoi RJ, Richman JS, Altom LK, Hawn MT (2014). The relationship between timing of surgical complications and hospital readmission. JAMA Surg, 149:348-54.
Thomas JW, Holloway JJ (1991). Investigating early readmission as an indicator for quality of care studies. Med Care, 29: 377-394.
Tsai TC, Joynt KE, Orav EJ, Gawande AA, Jha AK (2013). Variation in surgical-readmission rates and quality of hospital care. N Engl J Med, 369: 1134-1142.
Boockvar KS, Halm EA, Litke A, Silberzweig SB, McLaughlin M, Penrod JD,et al. (2003). Hospital readmissions after hospital discharge for hip fracture: surgical and nonsurgical causes and effect on outcomes. J Am Geriatr Soc, 51: 399-403.
French DD, Bass E, Bradham DD, Campbell RR, Rubenstein LZ (2008). Rehospitalization after hip fracture: predictors and prognosis from a national veterans study. J Am Geriatr Soc, 56: 705-710.
Charlson ME, Pompei P, Ales KL, MacKenzie CR (1987). A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis, 40: 373-383.
Khan MA, Hossain FS, Dashti Z, Muthukumar N (2012). Causes and predictors of early re-admission after surgery for a fracture of the hip. J Bone Joint Surg Br, 94: 690-697.
Hahnel J, Burdekin H, Anand S (2009). Re-admissions following hip fracture surgery. Ann R Coll Surg Engl, 91: 591-595.
Mosteller F, Gilbert JP, McPeek B (1980). Reporting standards and research strategies for controlled trials: agenda for the editor. Control Clin Trials, 1: 37-58.
Edelstein DM, Aharonoff GB, Karp A, Capla EL, Zuckerman JD, Koval KJ (2004). Effect of postoperative delirium on outcome after hip fracture. Clin Orthop Relat Res, 422: 195-200.
Foss NB, Kristensen MT, Kehlet H (2008). Anaemia impedes functional mobility after hip fracture surgery. Age Ageing, 37: 173-178.
Avenell A, Handoll HH (2010). Nutritional supplementation for hip fracture aftercare in older people. Cochrane Database Syst Rev, 18: CD001880.
Liu Y, Phillips M, Codde J (2001). Factors influencing patients’ length of stay. Aust Health Rev, 24: 63-70.
Becker C, Crow S, Toman J, Lipton C, McMahon DJ, Macaulay W,et al. (2006). Characteristics of elderly patients admitted to an urban tertiary care hospital with osteoporotic fractures: correlations with risk factors, fracture type, gender and ethnicity. Osteoporos Int, 17: 410-416.
Hawkes WG, Wehren L, Orwig D, Hebel JR, Magaziner J (2006). Gender differences in functioning after hip fracture. J Gerontol A Biol Sci Med Sci, 61: 495-499.
Kannegaard PN, van der Mark S, Eiken P, Abrahamsen B (2010). Excess mortality in men compared with women following a hip fracture. National analysis of comedications, comorbidity and survival. Age Ageing, 39: 203-209.
Lofman O, Berglund K, Larsson L, Toss G (2002). Changes in hip fracture epidemiology: redistribution between ages, genders and fracture types. Osteoporos Int, 13: 18-25.
Samuelsson B, Hedstrom MI, Ponzer S, Soderqvist A, Samnegard E, Thorngren KG,et al. (2009). Gender differences and cognitive aspects on functional outcome after hip fracture--a 2 years’ follow-up of 2,134 patients. Age Ageing, 38: 686-692.
Wehren LE, Hawkes WG, Orwig DL, Hebel JR, Zimmerman SI, Magaziner J (2003). Gender differences in mortality after hip fracture: the role of infection. J Bone Miner Res, 18: 2231-2237.
Endo Y, Aharonoff GB, Zuckerman JD, Egol KA, Koval KJ (2005). Gender differences in patients with hip fracture: a greater risk of morbidity and mortality in men. J Orthop Trauma, 19: 29-35.
Frihagen F, Nordsletten L, Madsen JE (2007). Hemiarthroplasty or internal fixation for intracapsular displaced femoral neck fractures: randomised controlled trial. BMJ, 335: 1251-1254.
Leonardsson O, Sernbo I, Carlsson, Akesson K, Rogmark C (2010). Long-term follow-up of replacement compared with internal fixation for displaced femoral neck fractures results at ten years in a randomised study of 450 patients. J Bone Joint Surg Br, 92: 406-412.
Keating JF, Grant A, Masson M, Scott NW, Forbes JF (2006). Randomized comparison of reduction and fixation, bipolar hemiarthroplasty, and total hip arthroplasty. Treatment of displaced intracapsular hip fractures in healthy older patients. J Bone Joint Surg Am, 88: 249-260.
Blomfeldt R, Toernkvist H, Ponzer S, Soederqvist A, Tidermark J (2005). Comparison of internal fixation with total hip replacement for displaced femoral neck fractures. Randomized, controlled trial performed at four years. J Bone Joint Surg Am, 87: 1680-1688