A Prospective Cohort Study of Lower-Extremity Pressure Ulcer Risk Among Bedfast Older Adults

Abstract

OBJECTIVE: To estimate the incidence and identify risk factors for lower-extremity pressure ulcers in bedfast older adult patients. DESIGN: Prospective cohort study. SETTING: A 500-bed long-term-care facility in Japan. PATIENTS: A total of 259 patients who were aged 65 years or older, confined to bed, and without lower-extremity pressure ulcers at enrollment participated in the study. MAIN OUTCOME MEASURES: Incidence of occurrence, wound characteristics, and risk factors for lower-extremity pressure ulcers. The incidence of lower-extremity pressure ulcers per 100 person-years was 16.8 (n = 33). The most common sites of lesions were the toes and heels. Cox regression analysis indicated that 3 factors were independently related to new lower-extremity pressure ulcer risk: low ankle-brachial index value (hazards ratio 0.075; 95% confidence interval [CI], 0.023-0.242), length of bedfast period (hazards ratio 1.010; 95% CI, 1.004-1.015), and male gender (hazards ratio 2.951; 95% CI, 1.450-6.009). Receiver operating characteristic curve analysis showed the area under the curve was 0.760 (95% CI, 0.675-0.844) for the ankle-brachial index. Therefore, an ankle-brachial index cutoff level of 0.8 provided high sensitivity and adequate specificity. CONCLUSION: Lower-extremity pressure ulcers are a significant problem in bedfast older adult patients aged 65 years or older. Bedfast older adult patients who developed lower-extremity pressure ulcers in this study were believed to have arteriosclerosis; the patients' ulcers exhibited features of ischemic ulcers. The findings of the present study suggest that bedfast older adult patients with a low ankle-brachial index value, a long bedfast period, or male gender should be closely monitored for lower-extremity pressure ulcer development on admission to long-term-care facilities. In particular, the ankle-brachial index is recommended as a screening tool in this practice setting.