A notable finding of the study here is that dietary modification is practiced irrespective of income level. This finding suggests that outlays for dietary modification are recognized as a very important and essential expense. It is also the least expensive item (compared with care foods and adaptive utensils) of those investigated here. There is also a statistically significantly lower BMI in participants eating porridge consistency rice, and eating porridge rice is significantly related to the severity of SD and PD. Functional disorders in PD participants would make rehabilitation of swallowing less effective than in participants with other etiologic diseases because disturbances in the oropharyngeal and esophageal phase in swallowing occurs in the early stage of PD [4]. Effects of L-dopa treatment on improvements in the functions of eating and swallowing have not been determined although functioning in the oral phase could improve and result in a better performance of the swallowing function [21]. Therefore, dietary modifications should be recommended in PD patients. The outlays for the dietary modifications are the smallest but the number of participants reporting dietary modifications is the largest among the directly SD-related items, showing that dietary modification plays a very important role to cope with SD (Table 2). Here, soft rice porridge is usually eaten with softened side dishes, suggesting the potential for malnutrition. Participants eating the modified foods would present the possibility of lower nutrition intakes [22]. In the study here the BMI is negatively related to the score of dietary modifications but not to the SD scores (Table 3), suggesting that a texture-modified diet may result in malnutrition expressed as a lower BMI. The BMI here was not significantly correlated with the severity of SD, age, or duration of PD like in other reports [23]. It has also been speculated that reduced energy intake and/or increased energy expended may be associated with body weight loss and lower BMI in PD [24].
The lower BMI here is associated with a lower energy intake caused by eating the porridge rice. In older adults consumption of only few varieties of energy-dense food should be avoided to prevent low BMI even in apparently healthy elderly persons [25], and malnutrition can be reversed with simple dietary education of older adults. While PD is a neurodegenerative disease and it is difficult to compare results based on other causes of SD with the results here, the findings in [24] may be relevant also in this case.
The caregiver is important in preventing lower BMI. The nutritional status of persons assisted by a Home Care Program and 100 % dependent on caregivers is determined by the caregiver educational level, not income [26]. Our report shows that in addition to BMI, incomes are not related to use and costs of SD-related items, however that dietary modification is the most effective activity to cope with SD and that it is related to a lower BMI. Therefore, improvement in the nutritional status in the PD participants (as well as in PD patients in general) could be attained by caregivers and relatives residing with the participants and being provided with nutritional information by dietitians and/or specially trained nurses.
Commercially available care foods are another choice playing a role in preventing malnutrition, and this has been shown for a variety of types of care food products [18]. The logistic analysis showed that BMI is strongly related to types of foods in the Results section above. The SD score in participants eating porridge rice plus care foods suffer from more advanced SD than the participants eating ordinary rice only but differences in BMI among the two groups are not statistically significant (Table 5). Figure 1 shows that a decrease in BMI is lessened by eating care foods in participants with severe SD, suggesting that care foods is of some help in guarding against malnutrition in the older and more severe SD participants. A variety of care foods could serve to provide increased dietary variety to maintain the BMI of those eating ordinary rice or porridge rice [25].
Older respondents and especially females are more likely to make use of care foods (10 females of 11 users). Physical disability may be a source of difficulty in shopping, cooking [27], and changing eating habits among older women [28]. However, here there is no tendency towards lower BMI and body weight loss related to gender. Care foods were shown to prevent malnutrition in the 10 females here in spite of the presence of advanced SD and PD. The number of participants reporting care foods (n = 11) is very small compared with that of all of the participants on a texture-modified diet (n = 58) likely because of its higher price [18]. More money was spent on care foods than on dietary modifications and the monthly outlays for care foods are the highest among the SD-related costs as shown in Table 2. Nobody reported eating care foods among the 32 participants who were still working as shown in Table 1, and the outlays for care foods are not associated with incomes as shown in Table 3. These results suggest that the need to cope with SD overcomes the higher costs for care foods in the 11 participants (Table 2).
There are two kinds of food supplements: one for additional energy and nutrition and the other for general well-being like with herbal supplements. The former has been shown to be effective but the usefulness of the latter is subject to controversy. The outlays for supplements are related to the score of SD, indicating that participants with more severe SD preferred the supplements (10.2 ± 9.5 vs. 6.9 ± 7.8, p < 0.025). The outlays for alternative therapies (like massage or acupuncture) are related to the outlays for supplements, suggesting that participants who use supplements spend more money on alternatives. Outlays for alternatives are positively related to the outlays for eating utensils. For participants using adaptive utensils, the SD score was higher than that for participants not using adaptive utensils (10.2 ± 9.6 vs 7.1 ± 7.9, p < 0.029). Motor disability makes it difficult to ingest foods, and adaptive utensils may be thought helpful to promote and extend the range of independent eating. Japanese massage has been reported to improve the shoulder range of movement, suggesting relief of muscle stiffness as something that would make eating easier [29].
Table 3 shows that the outlays for dietary modifications are not proportional to other variables as it has the lowest mean value in Table 2. However, the use of dietary modification is important in the management of SD because only the BMI is negatively related to the dietary modification score. The dietary modifications are provided by other persons rather than a result of buying more expensive commercially available foods. Table 4 shows that dietary modifications may be the work of caregivers and/or children rather than by the survey participants and so the cost of dietary modification was not considered critical in the effort to cope with SD. In Japan the spouse and/or daughters are assumed to play a role in caregiving [30]. Due to the costs of increasing care for participants (elderly SD sufferers), members of the family must take responsibility in caring for these participants even when the severity of PD is slight. When the severity of PD increases, the ages in both PD participants and the spouse are also higher (Table 1, Table 4), with the result that spouses find it difficult to care for PD participants in their care, and may finally have to live with child (ren) even when the spouse is alive (Table 4). Table 4 also shows that the PD participants here lived with child (ren) after losing the spouse when participants became older and the severity of PD advanced. As the severity of PD increased, the outlays for the health-care also increase [31]. The micro-costing study here also showed that outlays for coping with SD increase with the severity of PD. Use of care foods which are nourishing but expensive is not related to caregivers but negatively related to the presence of children residing with the participants concerned (Table 4). These findings suggest that participants living with children and/or spouses preferred modified diets, which were provided for them, in preference to care foods, resulting in higher risks of malnutrition.
Although care foods may be used for side dishes due to the higher prices, care foods play an important role in preventing malnutrition as shown in Table 5 and Fig. 1. A Government report on care foods has suggested that one problem is to improve understanding of the utility of care foods [18]. Among the participants interviewed here, there is a considerable number who have only little information on the usefulness of care foods although the number was not tabulated. As mentioned above, education and advice about the usefulness of care foods to caregivers should be provided by dietitians and /or specially trained nurses and everybody expressed hopes that prices of care foods would be cheaper, at a level where more of the survey participants could make use of them to assist in coping with malnutrition.
There are several limitations to the current study. It was shown that care foods may be effective to prevent malnutrition in patients who eat rice porridge. However, only an intervention study could prove the effectiveness of care foods for prevention of malnutrition. It would be desirable for this to be proved by an intervention examination before firm conclusions can be made. Further, in the current study SD-related costs were classified into 5 categories, but the median levels of the SD-related cost were the minimum values of the category. Therefore, it will need further study to distinguish smaller amounts in more detail. Finally, continued research with the participants studied here would be able to show how the results obtained here could affect the various factors considered in this paper.