Risk factors for failure to return to the pre-fracture place of residence after hip fracture: a prospective longitudinal study of 444 patients

The majority of the hip fracture patients in the studied population aged 65 years and older lived in their own home, whilst sustaining a hip fracture. During the first year after fracture treatment, three quarters of the surviving population had returned to their own home. Multivariable logistic regression analysis identified higher age, dementia and a lower level of mobility as the most important risk factors for failure to return to their own home at discharge, but also at 3- and at 12-month post-fracture.

The percentage of patients returning to their pre-fracture residence was stable between 3  and 12 months, the 3-month time mark can be used as an evaluation end point in future research. This is in line with a previous study which concluded that the 4-month time mark is adequate to evaluate ADL and residential status in hip fracture patients [16].

The medical and social morbidity of patients living in a residential home was worse compared to patients living in their own home, this is reflected in a higher 1-year mortality rate and a more limited level of mobility of the residential home patients. The overall 1-year mortality rate in our cohort (mean age 83 years) was 26%, comparable to the result of an US study (495 patients, mean age 85 years, 1-year mortality 26%) and a large Scottish cohort (27,475 patients, aged 50 and older, 1-year mortality 31%) [17, 18].

Early and reliable information on the potential discharge location after the hospital admission is of importance for both patients and caregivers to plan postoperative care. Furthermore, it is of socio-economical impact. When extrapolating the results of this study to different countries, one must be aware of bias at several levels. First, large differences between countries exist in type of housing and traditions for homes for elderly people [19]. In the Netherlands, a residential home is very heterogeneous form of living, as defined earlier in this paper. Secondly, large regional, national and international differences exist on discharge policies, like locations of discharge and availability of different kinds of temporary rehabilitation units [20, 21].

In a large Scottish series, the number of hip fracture patients living in their own home prior to sustaining a hip fracture and the percentage of these patients returning to this location after 4 months were comparable to our results [22]. In a series of hip fracture patients living in New York slightly more (85%) patients lived in their own residence prior to the hip fracture, but only 20% could be immediately discharged home from the hospital. At 6 months, 83% had returned back to their own residence [10]. Finally, in a comparison of a Finnish and a British cohort of hip fracture patients, 62 and 69% lived in their own home prior to the hip fracture, of whom 44 and 54% respectively, had returned home four  months after hospital discharge, which is less than that in our study [20].

Risk factors for not returning to their own home after hospital discharge were higher age, presence of dementia, absence of a partner, a lower level of mobility and a lower level of ADL prior to the hip fracture. Beside these risk factors, a longer LOS was also a risk factor for failure to return to their own home. A longer LOS is often associated with a higher rate of adverse outcomes during admission and might be related to worse outcome thereafter [23, 24]. LOS was not included in the statistical analysis, since the purpose of the current study was to identify risk factors known at admission of the patient. Subsequently, a prediction model for discharge location already at admission can be developed with these risk factors. If discharged to another location other than the patient’s own home, length of hospital stay is usually longer, with subsequent additional costs [5, 6]. An instrument that predicts the discharge location already at admission would therefore be of great value, not only for liaison services but also for patients and their family.

Advanced age, dementia, a walking disability and concomitant chronic systemic diseases were previously reported to be risk factors for failure to return to the patient’s own home at discharge from hospital [7]. This is largely in concordance with our findings, although we used a more general categorisation for scoring the overall degree of comorbidities (ASA classification). But, others have shown that ASA score and the number and type of comorbidities are associated [13]. We found a higher ASA score to be a significant risk factor in the bivariate analysis, but not in the multivariable logistic regression analysis. Other papers identified presence of a partner, good general health, good cognition, a higher level of ADL and mobility (both pre-fracture and 2 weeks after surgery), a lower number of medication, and moderate use of nursing interventions (like bathing) as important variables predicting discharge to an own residence [7‐10, 25, 26]. These findings are in line with our study. Other risk factors like anaemia at admission and fracture type were of small importance in the bivariate analysis and lost significance in the multivariable analysis. This is most probably because both anaemia and fracture type are strongly correlated to age, as shown in previous papers [27‐32].

Deakin et al. [9] published the largest series (3,240 patients) on discharge location of hip fracture patients. Their analyses were not specified for pre-fracture place of residence. Pre-injury dependence, age, male gender and injury sustained whilst in hospital were identified as the main risk factors for discharge to an alternative location (DAL). In contrast to their findings, we identified female gender as an independent risk factor for DAL This conflicting outcome is most probably due to difference in sample size between our and the former study. Furthermore, we only included patients admitted for a hip fracture at the emergency department; no patients with an in-hospital hip fracture were included.

Some limitations exist; first, the analyses of patients living in a residential home at admission were troubled by the limited numbers and a high mortality rate. At the 3-month follow-up, 86 patients could be analyzed; at 12 months only 66 patients. This is the main reason we could only identify age as a risk factor for failure to return to their residential home at discharge in the multivariate analysis. A lower level of ADL independency was the most important risk factor for not returning to their residential home in the bivariate analysis. A second limitation was the fact that the diagnosis of dementia was based on medical history. Cognitive performance was not assessed during hospital stay. The third limitation was that the type and number of comorbidities were not registered. Finally, many factors influence the location of residence after hospital discharge. Of these other factors, the role of the social network might be one of the largest. They can play an important role in the decision of an older person whether or not to stay living independently or to move to a residential home.

In conclusion, the large study population, the prospective character, adequate information on mortality rates and long follow-up make the study results valuable for analysis of socio-economic aspects after hip fracture treatment, especially for the patients living in their own home prior to hip fracture. This study identified higher age, dementia and a lower pre-fracture level of ADL as the most important independent risk factors for failure to return to the pre-fracture residence in patients living in their own home prior to hip fracture. In residential home patients, age was identified as the only risk factor, possibly due to the small patient numbers.

We will use these risk factors to develop a model that predicts discharge location at admission to provide better information for patients, family and physicians regarding the discharge and rehabilitation process.