Relation between hyponatraemia and falls by acute hospitalised patients: A case-control study

To investigate the possible association between hyponatremia and falls, in a sample of hospitalised adult patients.

In-hospital falls are a problem of major importance, provoking a significant decline in the quality of life of many patients. Recent studies have identified a relationship between such falls and the presence of hyponatremia.

Analytical retrospective observational case-control study.

The study population consisted of hospitalised patients who had suffered an in-hospital fall during the period 2014-2016. For each case, two controls who had not suffered any such fall were recruited. These cases and controls were matched according to gender, age, hospitalisation unit and date of admission. Study data were obtained from the hospital's record of falls, regarding the patients' socio-demographic factors, physical and psychological conditions and blood levels of sodium, potassium, urea and creatinine. The study is reported in accordance with STrengthening the Reporting of OBservational studies in Epidemiology guidelines.

The study sample consisted of 555 patients (185 cases and 370 controls). Hyponatraemia was detected in 57 cases (30.8%). A statistically significant relationship was found between the presence of hyponatraemia and the occurrence of falls: OR = 2.04. Other risk factors for falls were hypercreatinaemia OR 2.49, hyperuraemia OR 1.82, disorientation, need for ambulatory assistance and longer hospital stay.

From the study findings, we conclude that hyponatraemia is a predictor of falls by acute hospitalised patients. Further research is needed on the relationship between hypercreatinaemia, hyperuraemia and falls.

The assessment of risk factors for falls, such as hyponatraemia, can alert us to the possibility of this event occurring and facilitate the implementation of preventive measures. This parameter should be included as a significant new factor in assessment instruments designed to assess the risk of falls, thus enhancing the reliability and diagnostic validity of these instruments.