Pre-operative factors associated with increased mortality in elderly patients with a hip fracture: A cohort study in a developing country

Abstract

BackgroundHip fractures are a public health problem worldwide, and several factors are involved with post-operative mortality. The aim of this study was to identify the pre-operative factors associated with increased mortality in elderly patients with hip fractures in a developing country during the first post-operative year. MethodsAn ambidirectional cohort study was conducted with patients ≥ 65 years of age who underwent hip surgery due to a hip fracture caused by a fall from a standing position. Socio-demographic data, time to surgery, and comorbidities measured by the Charlson Comorbidity Index (CCI) were recorded. One-year mortality from all causes was the primary outcome, and 30-day and 6-month mortality were the secondary outcomes. Log-rank test was used to evaluate survival, and Cox’s proportional hazard regression was used to detect the factors associated with increased mortality. Results478 patients who underwent hip surgery were included in this study. The mean age was 80.2 ± 9.9, and 297 (62%) were females. There were 150 (31.4%) deaths at the end of the first follow-up year, and the mean of surgical delay was 8.8 days ± 6.4. Patients who underwent surgery during the first 4 days (Log-rank test < 0.001) after hip fracture occurred and patients with a CCI ≤ 2 (Log-rank test < 0.001) showed better survival (90%), comparing to mortality (52%) of patients with a CCI ≥ 3 and surgical delay > 4 days. The age ≥ 80 years (Hazard ratio 2.55 (HR), 95% confidence interval (CI) 1.70 to 3.84, p < 0.001), CCI ≥ 3 (HR 1.61, 95% CI 1.14–2.26, p 0.006), surgical delay > 4 days (HR 2.41, 95% CI 1.38–4.21, p 0.006), and haemoglobin < 10 g/dl (HR 1.51, 95% CI 1.06–2.15, p 0.02) were associated with increased 1-year mortality. In addition, 30-day mortality was associated with age ≥ 80 years (HR 4.15, 95% CI 1.98–8.70, p < 0.001), CCI ≥ 3 (HR 1.80, 95% CI 1.08–2.99, p 0.023), pre-surgical time >48 h (HR 3.0, 95% CI 1.58–5.92, p 0.001), and surgical delay > 4 days (HR 3.0, 95% CI 1.33–6.81, p 0.008); and 6-month mortality was associated with surgical delay > 4 days (HR 2.72, 95% CI 1.42–5.23, p 0.003), and haemoglobin < 10 g/dl (HR 1.56, 95% CI 1.04–2.33, p < 0.028). ConclusionsSurgical delay greater than 4 days and Charlson Comorbidity Index ≥ 3 were found as factors associated with increased mortality, along with anaemia < 10 g/dl and age ≥ 80 years. A similar mortality rate was found in this study compared to the rates reported by the literature, despite a surgical delay of 8.8 days.