Psychometric properties of Body Mass Index in screening malnutrition of COPD inpatients admitted at Nguyen Tri Phuong Hospital, Vietnam: a cross-sectional study

Abstract

This study assessed the validation of Body Mass Index (BMI) against Subjective Global Assessment (SGA), and identify the prevalence of malnutrition and its associated factors in Chronic Obstructive Pulmonary Disease (COPD) inpatients at Nguyen Tri Phuong Hospital, Ho Chi Minh City, Vietnam. A cross-sectional study was conducted to consecutively select COPD inpatients based on medical records and consultancy with doctors. A structured questionnaire was designed to collect socio-demographic characteristics, health status and comorbidities, nutritional status, and handgrip strength. Nutritional status was assessed using SGA and BMI. Handgrip strength was measured using a hand dynamometer. Health status was collected from medical records. The mean age of 83 COPD inpatients recruited in this study was 67 (SD=10.4) years. Most of the sample population was ≥60 years old (75%), male (86%), Kinh ethnic (89%), married (72%), not currently working (70%), and less than junior high school (81%). Nearly 68% had at least one comorbidity and 27% were active smokers. The mean handgrip strength was 21.6 kg (SD=8.7), and mean weight was 53.9 kg (SD=10.0). The mean BMI was 20.4 kg/m2 (SD=3.4) with 58% having BMI <21 kg/m2. SGA provided the prevalence of malnutrition of 65%. Age-group, BMI and handgrip strength were associated with malnutrition. A BMI cut-off point of <21 kg/m2 provided the highest ROC area of 84% (95%CI: 76%-92%). Malnutrition is common in COPD inpatients. This study confirms findings of previous studies that a BMI cut-off point of <21 kg/m2 was sensitive and specific for screening malnutritional risk at bedside.