ObjectiveTo investigate the risk factors influencing 1-year mortality after intramedullary nail fixation for fragile intertrochanteric fracture in elderly individuals.MethodsThe medical records of 622 consecutive elderly patients (aged ≥ 65 years) with fragile intertrochanteric fractures treated with proximal femoral nail anti-rotation (PFNA) and followed-up were retrospectively analyzed. The patients were divided into death and survival groups according to their survival status within 1 year after surgery, and the differences in age, sex, region of residence, tobacco use, alcohol use, body mass index (BMI), comorbidities (hypertension, diabetes mellitus, coronary heart disease, stroke, dementia, chronic obstructive pulmonary disease, pneumonia), preoperative hemoglobin, preoperative albumin, deep vein thrombosis, fracture type (AO classification), injury-to-surgery time, American Society of Anesthesiologists (ASA) score, anesthesia modality, duration of surgery, intraoperative blood loss, and blood transfusion were compared. The Kaplan–Meier method was used for univariate analysis to screen for statistically significant differences between the two groups, and the data were entered into the Cox proportional hazards model for multivariate analysis to determine independent risk factors affecting 1-year postoperative mortality. For subgroup analysis, we explored the varying effects of hypoproteinemia and being underweight in patients of different genders, as well as the effects of different age ranges, different injury-to-surgery times, and different blood transfusion volumes on 1-year postoperative mortality.ResultsThe mortality rates at 1, 3, and 6 months, and 1 year after surgery were 3.9%, 7.2%, 10.1%, and 15.3%, respectively. Univariate analysis showed that advanced age, male sex, tobacco use, underweight (BMI < 18.5), coronary heart disease, stroke, dementia, pneumonia, number of comorbidities ≥ 3, hypoproteinemia and injury-to-surgery time ≤ 2 days were associated with the 1-year postoperative survival status (P < 0.1). Multivariate analysis revealed that advanced age, male sex, dementia, number of comorbidities ≥ 3, hypoalbuminemia, and being underweight were independent risk factors for 1-year postoperative mortality. Subgroup analysis showed that being underweight was associated with 1-year postoperative mortality only in male patients but not in female patients, whereas hypoproteinemia was associated with 1-year postoperative mortality in both male and female patients. Furthermore, an injury-to-surgery time of less than 2 days improved patient survival, and patients more than 80 years old showed an elevated risk of postoperative mortality.ConclusionsPreoperative health status is a critical predictor of postoperative outcomes in elderly patients with fragile intertrochanteric fractures. Priority care should be given to the patients who are elderly, male, have dementia, have comorbidities, or are malnourished. Prompt nutritional reinforcement should be provided to patients with intertrochanteric fractures with comorbid hypoproteinemia and underweight. Furthermore, surgery should be performed as early as possible in patients with fewer comorbidities.