Factors Behind Fruit and Vegetable Consumption Among the Elderly with Functional Constipation: A Study Based on the Health Belief Model

The results of 2011 population census in Iran revealed that people above 60 years constituted 8.3% (ie, more than 6 million) of the total of 75 million population of Iran (1). Elderly population in Iran is estimated to reach 10 million (ie, around 10% of the total population) by the next 20 years (2).

Nutrition is a key component of the elderly’s health and quality of life, healthy aging, and disease prevention (3-5). Yet, little attention is paid to their nutritional status in developing countries (3). A study in Iran showed that 47.22% of the elderly had poor nutritional status (6). Another study also revealed that only 50.5% of them had good nutritional status (7). These findings highlight the necessity of assessing and improving their nutritional status (8).

One of the most common nutrition-related health problems among the elderly is bowel dysfunction, which can result in functional constipation (9). The prevalence of functional constipation among the elderly in Asia and Iran was reported to be 10.8% (10) and 21.3% (2), respectively. A study in Isfahan, Iran, showed that the prevalence of functional constipation increased with age and that 27.7% of people aged 50 or more suffered from the disorder (11). Another study in Kerman, Iran, also found that the prevalence of functional constipation among the elderly aged 65 or more was 36.9% (12).

Over time, constipation can cause different complications such as hemorrhoid, anal fissure, and rectal prolapse. Moreover, it negatively affects life, activities of daily living, and quality of life, and imposes considerable costs on patients. Therefore, it is considered as a significant health problem (13, 14).

A high fiber diet, which includes fruits and vegetables, has a significant role in preventing and managing constipation among the elderly. In other words, fruit and vegetable consumption is a key component of healthy eating, chronic illness prevention, and functional constipation management (15, 16). Studies show that about 1.7 million (or 2.5%) of all deaths in the world are related to inadequate fruit and vegetable consumption (17, 18). The world health organization (WHO) recommends that each person should consume at least 400 grams (or five servings) of fruits and vegetables per day (15, 19). Yet, a study in Iran showed that only 29% of the elderly had good dietary behaviors and that 70.5% of female and 76.6% of male elderly consumed inadequate level of fruits (8).

Dietary behaviors are usually assessed through health education and promotion models (8), such as the health belief model (HBM). HBM is used to assess health-related behaviors (20) including dietary behaviors (21). It comprises 5 main constructs, namely, perceived susceptibility, perceived severity, perceived benefits, perceived barriers, and cues to action. Perceived susceptibility is one’s opinion about the possibility of developing a given health problem, while perceived severity is one’s opinion about the seriousness of the problem and its complications, such as death, disability, or negative social outcomes related to employment, daily life, or social relationships. Moreover, perceived benefit is the opinion about the usefulness of a recommended behavior in minimizing the risk or the severity of the problem; and perceived barrier is the opinion about the actual and psychological costs of the recommended behavior. Cues to action include both internal and external cues (22). The present study aimed at assessing vegetable and fruit consumption of the elderly with functional constipation based on HBM.

This cross-sectional study was done on 163 elderly people aged 60 or more, who referred to retirement houses located in Isfahan, Iran, in 2013. Sampling was performed purposively. Accordingly, all elderly people in the study setting were screened for functional constipation, and then, 163 cases with the disorder were recruited.

The screening tool was the 6-item Rome III diagnostic criteria. Elderly people who reported experiencing at least 2 out of the 6 symptoms of the criteria in the last 3 months were diagnosed with functional constipation (14, 23). These criteria were personally completed by participants through a self-report method. Besides, a demographic questionnaire and a researcher-made HBM-related questionnaire were used for data collection. The items of the demographic questionnaire included age, gender, marital, educational, employment, and financial status, and living type (either alone or with family members). The data on financial status were collected through a self-report method (poor, average, good).The researcher-made HBM-related questionnaire contained 46 items in 7 subscales, namely, knowledge (8 items), perceived susceptibility (6 items), perceived severity (6 items), perceived self-efficacy (8 items), perceived benefits (6 items), perceived barriers (6 items), and cues to action (6 items). The items of the knowledge subscale were multiple-choice questions with 4 choices. Wrong and right answers to knowledge items were scored 0 and 1, respectively. Moreover, the items of the other subscales were scored on a 5-point Likert-type scale from 1 (“I’m not sure at all”) to 5 (“I’m completely sure”). All subscale scores were ranged from 0 to 100 scores. The questionnaire was developed based on the existing articles, books, and questionnaires (15, 24, 25). Then, its content validity was assessed by 7 experts in health education and nutrition. Their comments were used to revise the questionnaire. Reliability assessment was done via test-retest method, in which 25 persons completed the questionnaire for 2 times with a 15-day interval. The correlation coefficient between the 2 measurements was 0.78. Finally, 24-hour fruit and vegetable consumption was assessed using a checklist. All participants were asked to complete the questionnaires and the checklist.

This study was approved by Isfahan University of Medical Sciences, Isfahan, Iran (with the approval code of 392469).The aims of the study were explained to participants and their informed consent were obtained. Moreover, their questionnaires were anonymized.

Data were analyzed using SPSS software (V. 20.0). The measures of descriptive statistics were employed for data description, while inferential statistics methods, such as independent sample t test, Pearson correlation analysis, one-way analysis of variance, and multiple linear regression analysis, were used for data analysis. Significance level was set at less than 0.05.

Study participants were 85 female (52.1%) and 78 male (47.9%) elderly people with an age range of 60 to 86 and a mean age of 70.04 ± 6.49. They were mostly married (53.4%) and 31% of them lived alone.

The means of fruit, vegetable, and fruit and vegetable consumption among participants were 1.61 ± 0.73, 1.31 ± 0.87, and 2.92 servings per day, respectively. About 4.3% and 19.6% of participants did not consume fruits and vegetables, respectively. Moreover, 44.2% consumed less than 2 servings of fruits and 55.8% consumed less than 2 servings of vegetables per day. Around 10.4% consumed 3 servings or more of fruits and 6.1% consumed 3 servings or more of vegetables daily. Fruit and vegetable consumption was significantly correlated with income level, educational status, age, and living type (Table 1).

The results of Pearson correlation analysis revealed that fruit and vegetable consumption had significant positive correlations with perceived susceptibility, perceived severity, perceived self-efficacy, perceived benefits, and knowledge, and a significant negative correlation with perceived barriers (P < 0.001; Table 2).

Multiple linear regression analysis indicated that knowledge, perceived severity, perceived benefits, and perceived self-efficacy explained 58% of the total variance of fruit consumption, while knowledge, perceived benefits, and perceived self-efficacy explained 65.7% of the total variance of vegetable consumption (Table 3). The most important external cues to action from the perspectives of participants were television (57.7%) and family and relatives (46%). Moreover, the most important internal cue to action was abdominal distention (51.5%). Participants noted that these factors motivated them to consume fruit and vegetable.

This study was done based on HBM to evaluate fruit and vegetable consumption among elderly people with functional constipation. Findings revealed that fruit and vegetable consumption among the elderly was lower than the recommended levels. Hazavehei et al. (8) and Yang et al. (26) also reported the same finding. Viebig et al. also conducted a study in Brazil and found that 39% of their participating elderly people did not consume fruits and vegetables on a daily basis and only 19% consumed 5 servings of fruits and vegetables per day (27). The results of another study in Isfahan, Iran, also illustrated that the means of fruit and vegetable consumption among elderly males and females were 1.31 ± 4.5 and 1.28 ± 4.65 servings per day (28). In line with our findings, all these findings have indicated that the mean of fruit and vegetable consumption among Iranian elderly people is less that the recommended levels.

The findings of this study presented perceived self-efficacy and perceived benefits as the most significant predictors of fruit and vegetable consumption, which is in agreement with the findings of studies made by Najimi et al. on students (29) and Salehi et al. on the elderly (30, 31). Hazavehei et al. found that elderly people’s attitudes were significantly correlated with their nutritional status (8). Self-efficacy has been reported in different studies as one of the most important factors contributing to fruit and vegetable consumption (32-35). By definition, self-efficacy is one’s belief in his/her ability to accurately perform a given behavior (36).

Study findings also revealed that the level of participants’ knowledge was positively correlated with their fruit and vegetable consumption. Salehi et al. reported the same finding (31). Knowledge is a predisposing factor of engagement in healthy behaviors. Another finding of this study was the significant correlations of fruit and vegetable consumption with educational status and monthly income in that those elderly people who had higher educational status and income consumed larger amounts of fruits and vegetables. Previous studies also reported the same finding (27, 28, 37-39).

In line with the findings of previous studies (16, 30, 39), our findings also indicated financial factors, fruit and vegetable prices, and inadequate family support as the most significant barriers to fruit and vegetable consumption by the elderly. Moreover, findings revealed that the most important external cues to fruit and vegetable consumption were television and family and relatives. These findings are in line with the findings reported by Sharifirad et al. (40). Media coverage of health-related issues has turned media into the most significant source of health-related information for homebound elderly people.

Furthermore, we found that the mean scores of knowledge and self-efficacy among participating elderly people were low, while the mean scores of perceived susceptibility and severity were in the moderate range. These findings denote that most elderly people have limited information about or are inattentive to the importance of nutrition for functional constipation management, their susceptibility to functional constipation, and the severity of the complications of inadequate fruit and vegetable consumption. Moreover, these findings imply that not only the elderly do not pay attention to the benefits of fruit and vegetable consumption, but also there are many barriers to fruit and vegetable consumption.