Prevalence and associated factors of preoperative functional disability in elective surgical patients over 55 years old: a prospective cohort study

In preoperative settings, patients may have functional disabilities due to the disease for which surgery is being performed or comorbidities, but the associated and predictive factors remain unknown. This study examined the prevalence of preoperative functional disability and clarified the associated factors. Individuals aged 55 years who were scheduled to undergo surgery in a tertiary-care hospital in Japan between April 2016 and September 2016 were eligible for enrolment in the study. Patients with the diseases requiring psychiatric treatment and patients unable to complete the questionnaire without help were excluded. After obtaining informed consent, each patient was asked to complete the 12-item World Health Organization Disability Assessment Schedule-2.0, which is a standardized evaluation tool for assessing comprehensive living function. Data from these questionnaires and the patients' characteristics were evaluated. Multiple logistic regression analysis was conducted to determine independent factors associated with preoperative functional disability. Of 1201 recruited patients, 912 (75.9%) were included in our analysis. The prevalence of preoperative functional disability was 29.2%. Regression analysis identified six independent associated factors for preoperative functional disability: body mass index > 30 kg m(-2), mixed lung disease, serum albumin values, malnutrition, risk of malnutrition, and preoperative use of corticosteroids. In total, 29.2% of preoperative patients had functional disability. Obesity, nutritional deficiency, respiratory complications, and low serum albumin values were determined as potentially modifiable factors.