Adherences to oral nutritional supplementation among hospital outpatients: An online cross-sectional survey in Japan

Oral nutritional supplements (ONS) are multi-nutrient products used to increase the energy and nutrient intakes of patients. The aim of this study was to examine whether or not the adherence of patients varies according to their receiving prescription or over-the-counter ONS. Data were obtained from an online cross-sectional survey conducted with patients in Japan. A total of 107 patients who matched the inclusion criteria for the prescription ONS group and 148 who matched the criteria for the over-the-counter ONS group were further analyzed. In the prescription and over-the-counter ONS groups, the main medical reason for ONS consumption were “malnutrition” (48 patients [44.9%] vs. 63 patients [42.6%] p = 0.798], “frailty” (29 patients [27.1%] vs. 36 patients [24.3%] p = 0.663) and “aging” (25 patients [23.4%] vs. 30 patients [20.3%] p = 0.644). The proportion of “No particular disease” for prescription ONS consumption was significantly lower than that for over-the-counter ONS (6 patients [5.6%] vs. 24 patients [16.2%] p = 0.001). The body mass index of the prescription ONS group was significantly higher than that of the over-the-counter ONS group (21.1±4.38 kg/m(2) vs. 19.9±3.75 kg/m(2), p = 0.0161). In the prescription ONS group, all patients were given medical advice by doctors or registered dietitians. In contrast, in the over-the-counter ONS group, only 46 patients (31.1%) were given advice by doctors or registered dietitians (p<0.001). In the prescription ONS group, ONS was taken significantly more times and for a longer duration than in the over-the-counter ONS group (p<0.0001). However, among patients given advice by doctors or registered dietitians, there were no significant differences between the groups. Greater support by the medical team is still needed in order to maximize adherence to supplementation, especially concerning the calories, timing and period, so that benefits can be achieved and sustained.