Evaluate Five Different Diagnostic Tests for Dry Mouth Assessment in Geriatric Residents in Long-term Institutions in Taiwan

Yao-Ming Cheng; Shao-Huan Lan; Yen-Ping Hsieh; Shou-Jen Lan; Shang-Wei Hsu


BMC Oral Health. 2019;19(106) 

In This Article


Table 1 presents the residents demographic information. Of all 560 sampled residents, the majority (64.6%) lived in nursing homes. Their mean ADL score was 67.71 (95% CI, 65.28–70.14), indicating that most of these residents had mild disabilities. Female residents constituted the majority (55.4%). The residents had an average age of 77.1 years (95% CI, 76.14 year - 77.94 years), low educational attainment (79.6%) were illiterate or had only received an elementary school education), and were experiencing multiple diseases (mean = 2.08; 95% CI: 1.96–2.20). Their average length of stay in LTC was approximately 4 years (mean = 45.7 months; 95% CI: 42.57 months - 48.99 months). The residents' body mass index were within the normal range (mean = 22.91; 95% CI: 22.60–23.24). The residents' average ADL score was 67.71 (95% CI, 65.28–70.14), indicating they required minor help performing ADLs. The texture of food intake at the institution was mainly soft (53.0%). Furthermore, their self-estimated quantity of daily water intake was approximately 899.15 mL on average (95% CI, 851.15 mL – 947.17 mL).

All residents performed oral health care at least once per day in the form of brushing their teeth or gargling. However, 90% residents have not received dental examination within the past half year, suggesting that few of them visited dental clinics to examine their oral health status. In addition, The Self-perceived ability to chew food mean total score was 20.22 (95% CI, 19.45–20.98), indicating a moderate–high level of chewing ability (Table 2). The four categories of food each had a score of 8 points, and the residents' self-perceived chewing ability had a score exceeding 4 points, indicating that they still possessed satisfactory chewing ability. The mean score of chewing foods with fracturability (cooked vegetables) was the most satisfactory (5.87, 95% CI, 5.66–6.07), whereas the mean score of chewing foods with toughness (fresh foods and meats) was the least satisfactory (4.40, 95% CI, 4.17–4.60).

The average score of the residents' OHIP-7 T was 3.76 (95% CI, 3.25–4.28), indicating that they possessed satisfactory oral health-related quality of life (Table 3). Moreover, the mean score for self-perceived level of dry mouth was 16.02 (95% CI, 15.57–16.50), indicating that on average they perceived dryness in their mouth (Table 4). The mean of oral moisture measurement was 27.97 (95% CI, 27.63–28.31), which also suggested mouth dryness. The mean frequency of saliva swallowing measured by RSST was 2.97, which was on the borderline between normal and dry mouth; indicating that overall, the residents may tend to experience some degree of dry mouth (Table 4).

As shown in Table 1, Table 2, Table 3 and Table 4, the relationships between oral moisture measurement and other variables were verified using the correlation coefficient. A total of five variables achieved significance, namely ADL (r = 0.14, p < 0.01), frequency of tooth brushing a day (r = 0.11, p < 0.05), frequency of gargling a day (r = 0.12, p < 0.01) and RSST (r = 0.17, p < 0.01); these were all positively correlated with oral moisture measurement. The texture of food intake (r = − 0.09, p < 0.05) were negatively correlated with oral moisture measurement. The correlation coefficient indicated a low level of correlation between oral measurement and other variables.

Figure 3 shows the results of the CHAID decision tree analysis. Oral moisture measurement was the dependent variable and RSST results, tooth brushing behavior, and age were independent variables. The maximum tree depth was 3. The analysis revealed that RSST results was the most important variable (adjusted p < 0 .000; F = 12.793). RSST had three levels of risk: 1) A high risk of dry mouth suggested that the average value of oral moisture was SD: 26.39 and represented dry mouth level. The number of times saliva was swallowed was ≤1 (node 1): this indicated symptoms similar to that of dysphagia; 2) An average of oral moisture value of 27.96 indicated a moderate risk of dry mouth. The number of times saliva was swallowed was 1 to 3 (node 2); 3) An average oral moisture value of 28.827 suggested a low risk of dry mouth. This represented borderline dry mouth, and the number of times saliva was swallowed was over 3 (node3).

Figure 3.

Decision Tree constructed by CHAID algorithm

The number of times residents brushed their teeth was the next predictive variable for residents with a moderate risk of dry mouth (Adj. p < 0 .000, F = 7.568). Residents with a moderate risk of dry mouth who brushed their teeth more than once had an average oral moisture value of 28.59 (node5); this was higher than the average value of 27.20 (node 4) for residents who brushed their teeth once or less. This demonstrated that the number times residents brushed their teeth affected their oral moisture values if they had a moderate risk of experiencing dry mouth. For residents with a low risk of dry mouth, age is the next crucial predictive variable (adjusted p < 0.024, F = 9.295). The risk of experiencing borderline dry mouth in residents who were older than 68 years (the average oral moisture value was 28.564; node 7) was higher than that for residents who were aged 68 years or younger (the average oral moisture value was 29.481; node 6).