Hip fractures are common, costly and topical due to recent improvements in care secondary to national registries. Whilst each patient experiencing hip fracture is different, they share many variables and these variables can contribute to the individual's mortality risk.
Mortality risk assessment
Fragility hip fractures are both common and costly. Mortality post hip fracture has been reported previously at 10% at 30-days and 30% at 1-year.1 2 There have been a number of improvements regarding hip fracture care secondary to international audit in the form of national hip fracture registries. Data from the National Hip Fracture Database (UK) suggests a reduction in 30-day mortality secondary to audit.1 Evidence-based up-to-date information on mortality rates following hip fracture is important to guide (i) communication with the patient and their loved ones, (ii) local and national risk management, (iii) discharge planning and (iv) internal and external benchmarking.3
Recently, a number of research groups have developed weighted scoring systems with the aim of predicting mortality following fragility hip fracture. Examples of these prediction tools are the Nottingham Hip Fracture Score (NHFS),3 Orthopaedic Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (O-POSSUM), Estimation of Physiologic Ability and Surgical Stress (E-PASS), Charlson Comorbidity Index (CCI), Almelo Hip Fracture Score (AHFS), Hip Fracture Estimator of Mortality Amsterdam (HEMA), Hip-Multidimensional Frailty Score (Hip-MFS), National Hip Fracture Database Risk Model (UK) and others by Jiang et al and Holt et al.3-10 These tools differ in the patient’s admission variables used to create each risk model.
In 2012, the Irish Hip Fracture Database was established to improve the quality of hip fracture care in Ireland. Since then, in each of the 16 operating hospitals in Ireland, there are a number of variables recorded locally for each patient which suffers a fragility hip fracture.11 A number of these independent variables feature repeatedly in the medical literature due to their strength of correlation with mortality in this fragile patient cohort. Again, knowledge of evidence-based up-to-date information is important to highlight patient and system specific variables associated with increased risk of mortality in this fragile cohort.
To this end, we hereby review the current literature with respect to (i) gender, (ii) age, (iii) admission source and (iv) time-to-surgery with regards to their relationship with mortality following fragility hip fracture.
The “Weekend Effect”
The “weekend effect” is a hypothesis that patients admitted to hospital over the weekend have an increased risk of mortality than those admitted on weekdays.12 This subject has become topical in the National Health Service UK as the British government introduce measures to implement their “seven-day services” policy.13 We hereby review the current literature on the “weekend effect” with regards to fragility hip fracture-related mortality.
The literature regarding the ratios of female to male patients which suffer a fragility hip fracture is consistent at approximately 70:30.14 15 Whilst it is well documented that both sexes have excess mortality post hip fracture, male gender has repeatedly been shown to have a greater mortality excess than females.15 A large Norwegian study16 involving 81,867 patients with fragility hip fracture concluded a 4.6 fold higher excess one-year mortality in males and 2.8-fold excess in females versus age-matched non-hip fracture controls whilst Kristensen et al17 reported mortality in males as high as 2-fold higher compared to females. Similarly, Liu et al18 reported an almost twofold increase (HR 1.91). A multitude of separate studies consistently describe the male gender as a risk factor for excess mortality following hip fracture.19-25
Age is a well-established risk factor for increased risk of mortality post hip fracture in both sexes.21-23 26,27 Liu et al18 recently undertook a meta-analysis using 18 studies and a combined cohort of ~224,000 patients with fragility hip fractures and assessed the relationship between age and mortality. The authors concluded that there is a 1.51 increased risk of mortality (Hazard Ratio 1.51, p < 0.001) with increasing age.
In order to elucidate the relationship between increasing age (by decade) and mortality post hip fracture, Padron-Monedero et al28 undertook a cross-sectional study of those aged >65 years which were hospitalised in Spain during 2013 with a fragility hip fracture. After adjusting for comorbidities, using the 65-74-year-old cohort as a control group, the multivariate OR of mortality for those aged 75-84 was 2.11 and those aged >85 was 4.10, showing a clear relationship between increasing age and mortality risk.
Admission source: nursing home residency
There have been a number of studies which have aimed to delineate a relationship between those who are admitted from a nursing home and mortality risk following fragility hip fracture. Holvik et al29 sought to identify patient-related risk factors which predicted one-year mortality in a local fragility hip fracture group (n = 567) and concluded that admission from a nursing home was an independent predictor for one-year mortality (RR 3.24). Khan et al30 undertook a similar study but focused on 30-day mortality post fragility hip fracture in a retrospective study including 467 patients. This group found that patients admitted from either nursing/residential home was an independent risk factor for early mortality (OR 3.56).
Hannan et al31 collected mortality outcomes at 6 months on a similar set of patients (n = 571). Whilst this group established a clear correlation between nursing home residency and postoperative mobility at six months, they were unable to establish a similar relationship with mortality.
There have been many studies published within the medical literature which have investigated “surgical waiting time” or “time-to-surgery” and mortality risk in the fragility hip fracture cohort. Whilst it appears that shorter time-to-surgery results in a reduced rate of complications and length of stay, the outcomes regarding mortality risk are less conclusive.
In 2010, Leung et al32 performed a literature review including 42 peer-reviewed articles from 1980-2009. This group examined the relationships between “time-to-surgery” and both short and long term mortality. Having undertaken a detailed analysis of the available literature, the group concluded that the evidence was conflicting and that there was no conclusive evidence upon which to base a strict recommendation.
More recently, Nyholm et al33 found that surgical delay of >12, >24 and >48 hours increased 30-day mortality respectively (OR 1.45, p = 0.02, OR 1.34, p = 0.02 and OR 1.56, p = 0.02). They also found 90-day mortality increased with >48-hour surgical delay (OR 1.23, p = 0.04). Bohm et al34 established that having surgery within 48 hours demonstrated a decreased risk of in-hospital death (HR 0.51, 95% CI 0.41 – 0.63) and at one-year post operation (HR 0.72, 95% CI 0.64 – 0.80). Colais et al35 stated that those which were operated on within 2 days had lower 1-year mortality than those operated on after two days (HR 0.83, 95% CI 0.82-0.85). Rosso et al36 reported a decreased one-year mortality rate with surgery within 48 hours (OR 0.73, p = 0.0392). Cha et al37 demonstrated a significant correlation between both early (30-day) and late (one year) mortality with delayed surgery (>48 hours). Pincus et al38 established a significantly higher 30-day mortality risk with those operated >24 hours compared to <24 hours (6.5% vs 5.8%, % absolute RD, 0.79; 95% CI 0.23-1.35). This group concluded that a wait time of 24 hours may represent a “higher risk” threshold. Heyes et al39 reported a significantly increased one-year mortality risk in those operated > 36 hours. Maheshwari et al40 recommended urgent hip fracture surgery similar to that seen in stroke and myocardial ischaemia after they determined a 5% higher odds of one-year mortality per each 10-hour delay (OR 1.05, 95% CI 1.02-1.08, p = 0.001). Trinh et al41 also concluded that surgery within 48 hours is significantly associated with a decrease in mortality at one-year post-surgery.
In March 2018, Chang et al42 published a systematic review and meta-analysis regarding preventable risk factors of mortality after hip fracture surgery. This group described a statistically significant association between increased “time-to-surgery” (>2 days vs < 2 days; OR 1.91, 95% CI 1.14-3.18, p = 0.013) and mortality. This association was not present comparing <24 hours and >24 hours of surgical waiting time.
There have also been a number of recent studies which to the contrary, show no association between “time-to-surgery” and mortality risk. Choi et al43 investigated this relationship and reported no increased risk of short or long term mortality after adjusting for potential confounders, whether patients were operated on within three days, 3-7 days or >7 days. Meessen et al44 recorded mortality rates at one, six, 12 and 24 months postoperatively. This group established a relationship between male sex, >85 years and increased Charlson Comorbidity Index Score and mortality at two years, however, the surgical delay was not found to be a significant factor. Forni et al45 found no significant association between surgical delay and short term mortality risk (30-day). Lizaur-Utrilla et al46 investigated early versus late surgery and established that delaying surgery up to four days did not result in increased mortality risk at six or 12 months, however >4 days was associated with greater one-year mortality risk. Kelly-Pettersson et al47 ) examined the arbitrarily set time-constraints for surgery post hip fracture and reported an increased risk (12%) of a serious adverse event with every 10-hours of waiting time and increased the length of stay of 0.6 days with every 24-hours of waiting time. However, the group found no correlation between “time-to-surgery” and one-year mortality.
Although it is nearly 10 years since Leung et al32 undertook their literature review on this topic, it is clear that at this moment in time, the evidence remains conflicting.
The “Weekend Effect”
Since 2012, there have been nine large global studies examining the mortality effect of a weekend admission for a patient which has suffered a fragility hip fracture. Two of these papers demonstrated a correlation between weekend admission and increased mortality whilst five reported no difference between weekday and weekend admission. The remaining two suggested a decreased mortality risk when the patient was admitted over the weekend.48-56
Thomas et al57 retrospectively reviewed 2,989 hip fracture patients over a five-year period in the UK. Whilst the group reported no increased mortality with weekend surgery, they reported increased 30-day mortality risk for all hip fracture patients admitted over the weekend, whether managed operatively or non-operatively (OR 1.4, 95% CI 1.02-1.80; p = 0.032). Kristiansen et al58 retrospectively examined the 30-day mortality risk in a large group of hip fracture patients (n = 25,305) in Denmark. This group concluded that the 30-day mortality risk was higher in those admitted at the weekend (OR 1.13, 95% CI 1.04-1.23).
Sheikh et al59 prospectively assessed 1,326 hip fracture patients (UK) for differences in admission days and mortality risk and concluded there was no difference between weekday or weekend admission with regards to 30-day, 90-day or one-year mortality risk. Nijland et al60 retrospectively collected mortality information with respect to 1,803 patients in a hip fracture cohort in the Nederlands. This group recorded no association between weekend admission and increased 30-day or one-year mortality. Mathews et al61 prospectively collected information with respect to 816 hip fractures patients in a teaching hospital in the UK. This group concluded that weekend admission was not associated with increased risk of 30-day or 120-day mortality. Daugaard et al62 retrospectively reviewed data collected on 38,020 hip fracture patients admitted over an eight-year period in Denmark. Their investigations showed that there was no difference in mortality risk in their large cohort between those admitted during the weekdays versus the weekends. Neuberger et al63 studied fragility hip fracture-related 30-day mortality using data from 52,599 patients presenting to NHS hospitals (162 units) over 2014. Specifically assessing for differences in outcomes between those admitted on weekends versus weekdays, this group found no difference between both groups.
Boylan et al64 retrospectively analysed 344,989 hip fracture patients admitted over a 13-year period in an orthopaedic department in New York, USA. This group reported decreased short term mortality in patients admitted at the weekend versus those admitted during the weekdays (OR 0.94, 95% CI 0.89-0.99). Nandra et al65 examined a group of 2,060 hip fracture patients retrospectively treated in a UK hospital. They reported marginally lower 30-day mortality in those admitted at the weekend versus weekday (9.7% vs 10.2%), however, this finding was not statistically significant (OR 0.94, 95% CI 0.67-1.32). The group found “no significant weekend effect”.
These studies do not present a conclusive significant repeated “weekend effect”. The above research articles report heterogenous and conflicting findings. The outcome data for some ~470,000 patients are presented above. Whilst five of the nine studies include <3000 patients per cohort, the remaining four large studies included 25,308, 38,020, 52,599 and 344,989 patients, each of which reported an increased risk, two studies showing no difference and a decreased mortality risk respectively.
There is a multitude of research studies on fragility hip fractures and those variables which are associated with an increased risk of mortality following a fragility hip fracture. This article summarises the most up-to-date literature above on gender, age, nursing home residency, time-to-surgery and the “weekend effect”. Whilst there appears to be agreement on the impact of male gender, increasing age and nursing home residency on mortality, more research is required to delineate the relationship between time-to-surgery and the “weekend effect” and mortality at one-year.
Downey C, Quinlan JF, Department of Trauma & Orthopaedics, Tallaght University Hospital, Dublin 24, Ireland
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- Liu Y, Wang Z, Xiao W. Risk factors for mortality in elderly patients with hip fractures: a meta-analysis of 18 studies. Aging Clin Exp Res. 2018;30(4):323-30.
- Haentjens P, Magaziner J, Colon-Emeric CS, Vanderschueren D, Milisen K, Velkeniers B, et al. Meta-analysis: excess mortality after hip fracture among older women and men. Ann Intern Med. 2010;152(6):380-90.
- Sheikh HQ, Hossain FS, Aqil A, Akinbamijo B, Mushtaq V, Kapoor H. A Comprehensive Analysis of the Causes and Predictors of 30-Day Mortality Following Hip Fracture Surgery. Clin Orthop Surg. 2017;9(1):10-8.
- Muraki S, Yamamoto S, Ishibashi H, Nakamura K. Factors associated with mortality following hip fracture in Japan. J Bone Miner Metab. 2006;24(2):100-4.
- Ariza-Vega P, Kristensen MT, Martin-Martin L, Jimenez-Moleon JJ. Predictors of long-term mortality in older people with hip fracture. Arch Phys Med Rehabil. 2015;96(7):1215-21.
- Paksima N, Koval KJ, Aharanoff G, Walsh M, Kubiak EN, Zuckerman JD, et al. Predictors of mortality after hip fracture: a 10-year prospective study. Bull NYU Hosp Jt Dis. 2008;66(2):111-7.
- 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(6):676-85.
- Forsen L, Sogaard AJ, Meyer HE, Edna T, Kopjar B. Survival after hip fracture: short- and long-term excess mortality according to age and gender. Osteoporos Int. 1999;10(1):73-8.
- Roche JJ, Wenn RT, Sahota O, Moran CG. Effect of comorbidities and postoperative complications on mortality after hip fracture in elderly people: prospective observational cohort study. BMJ. 2005;331(7529):1374.
- Kilci O, Un C, Sacan O, Gamli M, Baskan S, Baydar M, et al. Postoperative Mortality after Hip Fracture Surgery: A 3 Years Follow Up. PLoS One. 2016;11(10):e0162097.
- Padron-Monedero A, Lopez-Cuadrado T, Galan I, Martinez-Sanchez EV, Martin P, Fernandez-Cuenca R. Effect of comorbidities on the association between age and hospital mortality after fall-related hip fracture in elderly patients. Osteoporos Int. 2017;28(5):1559-68.
- Holvik K, Ranhoff AH, Martinsen MI, Solheim LF. Predictors of mortality in older hip fracture inpatients admitted to an orthogeriatric unit in oslo, norway. J Aging Health. 2010;22(8):1114-31.
- Khan MA, Hossain FS, Ahmed I, Muthukumar N, Mohsen A. Predictors of early mortality after hip fracture surgery. Int Orthop. 2013;37(11):2119-24.
- Hannan EL, Magaziner J, Wang JJ, Eastwood EA, Silberzweig SB, Gilbert M, et al. Mortality and locomotion 6 months after hospitalization for hip fracture: risk factors and risk-adjusted hospital outcomes. JAMA. 2001;285(21):2736-42.
- Leung F, Lau TW, Kwan K, Chow SP, Kung AW. Does timing of surgery matter in fragility hip fractures? Osteoporos Int. 2010;21(Suppl 4):S529-34.
- Nyholm AM, Gromov K, Palm H, Brix M, Kallemose T, Troelsen A, et al. Time to Surgery Is Associated with Thirty-Day and Ninety-Day Mortality After Proximal Femoral Fracture: A Retrospective Observational Study on Prospectively Collected Data from the Danish Fracture Database Collaborators. J Bone Joint Surg Am. 2015;97(16):1333-9.
- Bohm E, Loucks L, Wittmeier K, Lix LM, Oppenheimer L. Reduced time to surgery improves mortality and length of stay following hip fracture: results from an intervention study in a Canadian health authority. Can J Surg. 2015;58(4):257-63.
- Colais P, Di Martino M, Fusco D, Perucci CA, Davoli M. The effect of early surgery after hip fracture on 1-year mortality. BMC Geriatr. 2015;15:141.
- Rosso F, Dettoni F, Bonasia DE, Olivero F, Mattei L, Bruzzone M, et al. Prognostic factors for mortality after hip fracture: Operation within 48 hours is mandatory. Injury. 2016;47 Suppl 4:S91-S7.
- Cha YH, Ha YC, Yoo JI, Min YS, Lee YK, Koo KH. Effect of causes of surgical delay on early and late mortality in patients with proximal hip fracture. Arch Orthop Trauma Surg. 2017;137(5):625-30.
- Pincus D, Ravi B, Wasserstein D, Huang A, Paterson JM, Nathens AB, et al. Association Between Wait Time and 30-Day Mortality in Adults Undergoing Hip Fracture Surgery. JAMA. 2017;318(20):1994-2003.
- Heyes GJ, Tucker A, Marley D, Foster A. Predictors for 1-year mortality following hip fracture: a retrospective review of 465 consecutive patients. Eur J Trauma Emerg Surg. 2017;43(1):113-9.
- Maheshwari K, Planchard J, You J, Sakr WA, George J, Higuera-Rueda CA, et al. Early Surgery Confers 1-Year Mortality Benefit in Hip-Fracture Patients. J Orthop Trauma. 2018;32(3):105-10.
- Trinh LTT, Achat H, Loh SM, Pascoe R, Asarreh H, Stubbs J. Meeting Management Standards and Improvement in Clinical Outcomes Among Patients With Hip Fractures. J Healthc Qual. 2018.
- Chang W, Lv H, Feng C, Yuwen P, Wei N, Chen W, et al. Preventable risk factors of mortality after hip fracture surgery: Systematic review and meta-analysis. Int J Surg. 2018;52:320-8.
- Choi HJ, Kim E, Shin YJ, Choi BY, Kim YH, Lim TH. The timing of surgery and mortality in elderly hip fractures: A retrospective, multicenteric cohort study. Indian J Orthop. 2014;48(6):599-604.
- Meessen JM, Pisani S, Gambino ML, Bonarrigo D, van Schoor NM, Fozzato S, et al. Assessment of mortality risk in elderly patients after proximal femoral fracture. Orthopedics. 2014;37(2):e194-200.
- Forni S, Pieralli F, Sergi A, Lorini C, Bonaccorsi G, Vannucci A. Mortality after hip fracture in the elderly: The role of a multidisciplinary approach and time to surgery in a retrospective observational study on 23,973 patients. Arch Gerontol Geriatr. 2016;66:13-7.
- Lizaur-Utrilla A, Martinez-Mendez D, Collados-Maestre I, Miralles-Munoz FA, Marco-Gomez L, Lopez-Prats FA. Early surgery within 2 days for hip fracture is not reliable as healthcare quality indicator. Injury. 2016;47(7):1530-5.
- Kelly-Pettersson P, Samuelsson B, Muren O, Unbeck M, Gordon M, Stark A, et al. Waiting time to surgery is correlated with an increased risk of serious adverse events during hospital stay in patients with hip-fracture: A cohort study. Int J Nurs Stud. 2017;69:91-7.
- Brozek W, Reichardt B, Kimberger O, Zwerina J, Dimai HP, Kritsch D, et al. Mortality after hip fracture in Austria 2008-2011. Calcif Tissue Int. 2014;95(3):257-66.
- Marques A, Lourenco O, da Silva JA, Portuguese Working Group for the Study of the Burden of Hip Fractures in P. The burden of osteoporotic hip fractures in Portugal: costs, health related quality of life and mortality. Osteoporos Int. 2015;26(11):2623-30.
- Klop C, Welsing PM, Cooper C, Harvey NC, Elders PJ, Bijlsma JW, et al. Mortality in British hip fracture patients, 2000-2010: a population-based retrospective cohort study. Bone. 2014;66:171-7.
- Poenaru DV, Prejbeanu R, Iulian P, Haragus H, Popovici E, Golet I, et al. Epidemiology of osteoporotic hip fractures in Western Romania. Int Orthop. 2014;38(11):2329-34.
- Tucker A, Donnelly KJ, McDonald S, Craig J, Foster AP, Acton JD. The changing face of fractures of the hip in Northern Ireland: a 15-year review. Bone Joint J. 2017;99-B(9):1223-31.
- Folbert EC, Hegeman JH, Vermeer M, Regtuijt EM, van der Velde D, Ten Duis HJ, et al. Improved 1-year mortality in elderly patients with a hip fracture following integrated orthogeriatric treatment. Osteoporos Int. 2017;28(1):269-77.
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- Haugan K, Johnsen LG, Basso T, Foss OA. Mortality and readmission following hip fracture surgery: a retrospective study comparing conventional and fast-track care. BMJ Open. 2017;7(8):e015574.
- Magnusson KA, Gunnarsson B, Sigurdsson GH, Mogensen B, Olafsson Y, Karason S. [Treatment and outcome of patients with hip fracture]. Laeknabladid. 2016;102(3):119-25
- Thomas CJ, Smith RP, Uzoigwe CE, Braybrooke JR. The weekend effect: short-term mortality following admission with a hip fracture. Bone Joint J. 2014;96-B(3):373-8.
- Kristiansen NS, Kristensen PK, Norgard BM, Mainz J, Johnsen SP. Off-hours admission and quality of hip fracture care: a nationwide cohort study of performance measures and 30-day mortality. Int J Qual Health Care. 2016;28(3):324-31.
- Sheikh HQ, Aqil A, Hossain FS, Kapoor H. There is no weekend effect in hip fracture surgery - A comprehensive analysis of outcomes. Surgeon. 2017.
- Nijland LMG, Karres J, Simons AE, Ultee JM, Kerkhoffs G, Vrouenraets BC. The weekend effect for hip fracture surgery. Injury. 2017;48(7):1536-41.
- Mathews JA, Vindlacheruvu M, Khanduja V. Is there a weekend effect in hip fracture patients presenting to a United Kingdom teaching hospital? World J Orthop. 2016;7(10):678-86.
- Daugaard CL, Jorgensen HL, Riis T, Lauritzen JB, Duus BR, van der Mark S. Is mortality after hip fracture associated with surgical delay or admission during weekends and public holidays? A retrospective study of 38,020 patients. Acta Orthop. 2012;83(6):609-13.
- Neuburger J, Currie C, Wakeman R, Georghiou T, Boulton C, Johansen A, et al. Safe working in a 7-day service. Experience of hip fracture care as documented by the UK National Hip Fracture Database. Age Ageing. 2018.
- Boylan MR, Rosenbaum J, Adler A, Naziri Q, Paulino CB. Hip Fracture and the Weekend Effect: Does Weekend Admission Affect Patient Outcomes? Am J Orthop (Belle Mead NJ). 2015;44(10):458-64.
- Nandra R, Pullan J, Bishop J, Baloch K, Grover L, Porter K. Comparing mortality risk of patients with acute hip fractures admitted to a major trauma centre on a weekday or weekend. Sci Rep. 2017;7(1):1233