Characteristics of drugs with oral frailty patients among community pharmacy visitors: a cross-sectional study

Abstract

Background

With the rise in the older population, it has become important to understand the relationship between oral frailty and drug use to consider appropriate medical interventions and drug use for older persons.

Objective

To clarify the relationship among oral frailty, drug use, and other patient backgrounds and to identify relevant factors using information from patient questionnaires and pharmacy medication history records.

Methods

This cross-sectional study involved community-dwelling older adults. Older adults aged ≥ 65 years who visited 44 pharmacies in Tochigi Prefecture, Japan, with their prescriptions between July 1 and September 10, 2021, and who were able to complete the questionnaire independently were eligible for the study. An oral Frailty Index-8 score ≥ 4 was used to define the oral frailty group, while a score of 0–3 was used to define the non-oral frailty group. A multivariate logistic regression analysis was conducted to identify relevant factors for oral frailty, with oral frailty as the dependent variable and items from the questionnaire and drug survey as independent variables.

Results

A total of 1,386 eligible participants were included in this study, and 761 (54.9%) had oral frailty. Multivariate logistic regression analysis showed that frailty, number of natural teeth (fewer than 20), and benzodiazepine use were significantly associated with oral frailty (p < 0.001, p < 0.001, and p = 0.037, respectively).

Conclusions

Our results will provide evidence for community pharmacists to provide appropriate patient education, recommend consultations with dental care providers, and assist in community healthcare coordination.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-024-05299-y.

Background

With the aging Japanese population, it has become important to extend healthy life expectancy and build a healthy society with longevity. Healthy life expectancy is the period during which people can live without limitations caused by health problems. The gap between average life expectancy and healthy life expectancy is considered an unhealthy period [1]. It is important to reduce this gap to maintain quality of life.

In recent years, significant attention has been paid to “frailty,” a condition characterized by increased vulnerability to stress due to a decline in a physiological reserve capacity with aging. This condition may lead to impairment in daily functioning and the need for nursing care [2–4]. Similarly, “oral frailty” refers to a series of phenomena and processes, from changes in oral conditions associated with aging to functional impairment due to increased oral vulnerability, ultimately leading to a decline in physical and mental functions [5]. Because these conditions fall between health and functional impairment and are reversible, appropriate intervention and support by healthcare professionals are required [2, 4, 5].

In a super-aging society, an important issue, in addition to frailty and oral frailty, is that older adults often have multiple diseases and physiological decline requiring multiple medications, which leads to increased adverse drug events [6]. Potentially Inappropriate Medication (PIM) criteria have been established in Japan [7], the US [8], and Europe [9, 10] and are being applied to encourage proper medication use in older adults. Among the drugs on this list, those with sedative or anticholinergic properties are known to cause xerostomia and extrapyramidal symptoms resulting from dysphagia [11].

It is important to understand the relationship between oral frailty and drug use to consider appropriate medical interventions and drug use for older adults. Oral frailty has been suggested to be associated with frailty [12–15]. In addition, several studies have revealed associations between frailty and polypharmacy, PIM, and the use of sedative or anticholinergic drugs [16–19]. However, there are few reports on the association between oral frailty and drug use.

The purpose of this study was to clarify the relationship among oral frailty, drug use, and other patient background characteristics and to identify relevant factors using information from patient questionnaires and pharmacy medication history records.

Methods

Study design and patients

This was a cross-sectional study involving community-dwelling older adults. Older adults aged 65 years or older who visited 44 pharmacies in Tochigi Prefecture, Japan, with their prescriptions between July 1 and September 10, 2021, and who were able to complete the questionnaire on their own were eligible for the study. The exclusion criterion was a body mass index (BMI) < 5 kg/m² or > 100 kg/m² [20].

This study was conducted in compliance with the “Ethical Guidelines for Medical Research Involving Human Subjects” and approved by the Ethical Review Committee of Tokyo University of Science (approval number: 20024).

Study method

Patient questionnaires and drug use surveys were conducted at pharmacies by pharmacists with prior training. The patient questionnaire was administered using Google Forms [21]. Patients who could operate a tablet device without assistance entered their responses themselves, whereas those who were unable to operate a tablet answered the questions on paper, while the pharmacy staff transcribed their responses into the Google Form. Drug use was investigated based on the prescription drug name, dosage, and administration at the time of the survey using the pharmacy medication history record.

Before the patient questionnaire survey, informed consent was conducted based on the explanatory document for patients, which explained the purpose of the study, the disadvantages associated with participating in the study, and the withdrawal of consent. Patients who could operate a tablet device without assistance operated a tablet device checked the study explanation and consent section in the patient questionnaire Google form, and only patients who consented entered their responses into the tablet device. Patients who were unable to operate a tablet answered the consent section on paper.

Patient questionnaire

The questionnaire comprised 21 items, including the Oral Frailty Index-8 (eight items) [22, 23], Frailty Screening Index (five items) [24], age, sex, height, weight, drinking status, smoking status, number of natural teeth (< 20 or ≥ 20), and nutritional counseling experience. Height and weight were converted to BMI instead of being used individually, as in the case of identifying relevant factors.

The Oral Frailty Index-8 is an oral frailty assessment checklist proposed by the Japan Dental Association and is commonly used in Japan [22, 23]. The checklist comprises eight questions that require yes or no answers [22, 23]: (1) Do you have any difficulties eating tough foods compared to 6 months ago? (Yes: 2 points, No: 0 points). (2) Have you choked on your tea or soup recently? (Yes: 2 points, No: 0 points). (3) Denture use (Yes: 2 points, No: 0 points). (4) Do you often experience a dry mouth? (Yes: 1 point, No: 0 point). (5) Do you go out less frequently than you did last year? (Yes: 1 point, No: 0 point). (6) Can you eat hard foods like squid jerky or pickled radish? (Yes: 0 points, No: 1 point). (7) How many times do you brush your teeth per day? (< 3 times/day) (Yes: 0 points, No: 1 point). (8) Have you visited a dental clinic at least annually? (Yes: 0 points, No: 1 point). Depending on the score, 0–2 points indicate a low risk of oral frailty, 3 points indicate a moderate risk of oral frailty, and ≥ 4 points indicate a high risk of oral frailty.

The Frailty Screening Index was proposed by Yamada & Arai [24], and validation studies have been conducted. The tool comprises five yes-or-no questions: (1) Have you lost 2 kg or more in the past 6 months? (Yes: 1 point, No: 0 point). (2) Do you think you walk slower than before? (Yes: 1 point, No: 0 point). (3) Do you go for a walk for your health at least once a week? (Yes: 0 points, No: 1 point). (4) Can you recall what happened 5 min ago? (Yes: 0 points, No: 1 point). (5) In the last 2 weeks, have you felt tired without a reason? (Yes: 1 point, No: 0 point). A score of 3 or higher is assessed as frailty [24].

Patient drug use

Drugs obtained from the pharmacy during the patient questionnaire survey were assessed [25]; [19]. The following endpoints were evaluated using these data: total number of drugs, presence or absence of polypharmacy, PIM use, and sedative or anticholinergic drug use.

The total number of drugs and polypharmacy accounted for drugs with systemic effects in the chronic phase, including oral, self-injectable, and systemic external drugs [25]. Polypharmacy is defined as the administration of five or more drugs [25, 26]. Acute prescription drugs (used within 7 d), including topical, rescue, and over-the-counter drugs, were excluded [25]. Oral drugs were defined as tablets, capsules, dispersions, granules, and liquids [26]. Topical drugs, such as poultices, non-steroidal anti-inflammatory drugs, ointments, eye drops, and nasal sprays, were also excluded [26]. However, topical drugs with systemic effects, such as nitro patches, β₂ agonist patches, β antagonist patches, β₂ agonist inhalers, and anticholinergic inhalers, were included [26]. A drug with multiple specifications was considered a single drug [27]. The presence of PIM was determined based on the Beers Criteria [8]. Use and categories of sedative or anticholinergic drugs were determined based on previous studies [28, 29].

Statistical analysis

Using the Oral Frailty Index-8, a score of ≥ 4 defined the oral frailty group, while a score of 0–3 defined the non-oral frailty group [23]. To analyze relevant factors for oral frailty, we first compared patient background and drug used between the oral frailty and non-oral frailty groups in a univariate analysis. Comparisons of age, BMI, and total number of drugs were evaluated using the Mann–Whitney U test, while other items were evaluated using the χ² test or Fisher’s exact probability test. To avoid multicollinearity, Spearman correlation coefficients with p-values < 0.05 were estimated for the relationships among the extracted factors. If there was a strong correlation between factors (Spearman correlation coefficient: |ρ| > 0.8), one factor was selected as clinically important. Multivariate logistic regression analysis was performed to identify relevant factors for oral frailty, with oral frailty as the dependent variable and the extracted items as independent variables. The Hosmer–Lemeshow test, a measure of goodness of fit for the logistic regression model, was conducted. Further analysis of association between the number of these relevant factors and oral frailty was performed. Pearson’s chi-square test was used for these relationships and Bonferroni’s test was used for multiple comparisons. The significance level was set at p < 0.05. All analyses were performed using R version 4.2.2 (The R Foundation for Statistical Computing, Vienna, Austria).

Results

Patient characteristics

Data from 1,409 patients were collected during the questionnaire and drug use surveys. After applying the exclusion criterion based on BMI, the total number of eligible participants was 1,386. Among the 1,386 eligible participants, more than half, 761 (54.9%), had oral frailty, while less than a quarter, 272 (19.6%), were classified as frailty. The median age of the participants was 74.0 years (range: 65.0–94.0), and more than half (57.2%) were women (Table 1). The proportion of patients with frailty was approximately 2.4 times higher in the oral frailty group (26.5%) than that in the non-oral frailty group (11.2%). Age and frailty prevalence were significantly higher in the oral frailty group than in the non-oral frailty group (p < 0.001). In addition, the proportion of patients with fewer than 20 natural teeth, the total number of drugs, the prevalence of polypharmacy, and the rate of benzodiazepine use were significantly higher in the oral frailty group than that in the non-oral frailty group (p < 0.001, p = 0.003, p = 0.005, and p = 0.001, respectively).

Table 1.

Patient characteristics

Characteristicsa	Oral Frailty (n = 761)	Non-oral frailty (n = 625)	p value
Age	74.0(65.0–94.0)	73.0(65.0–91.0)	< 0.001	***
Sex
Female	320(42.0)	273(43.7)	0.578
Male	441(58.0)	352(56.3)
Body mass index (kg/m )2	23.3(14.5–39.5)	23.1(13.1–36.3)	0.516
Frailty	202(26.5)	70(11.2)	< 0.001	***
Alcohol consumption
Rarely	479(62.9)	394(63.0)	0.998
Sometimes	136(17.9)	112(17.9)
Every day	146(19.2)	119(19.0)
Smoking (habitually)	60(7.9)	38(6.1)	0.231
Number of natural teeth (< 20)	512(67.3)	193(30.9)	< 0.001	***
Nutrition counseling experience	26(3.4)	16(2.6)	0.442
Total number of drugs	4.0(0.0–30.0)	3.0(0.0–14.0)	0.003	**
Polypharmacy (≥ 5)	294(38.6)	195(31.2)	0.005	**
PIMs use	182(23.9)	124(19.8)	0.079
Sedative or anticholinergic drug use	233(30.6)	164(26.2)	0.083
Categories of sedative or anticholinergic drugs
Benzodiazepine	125(16.4)	63(10.1)	0.001	**
Muscarinic receptor antagonist	53(7.0)	38(6.1)	0.581
Antihistamines	34(4.5)	36(5.8)	0.332
Antiepileptic drug	32(4.2)	26(4.2)	1.000
Opioid receptor agonist	15(2.0)	12(1.9)	1.000
Antidepressants	10(1.3)	7(1.1)	0.810
Antipsychotics	12(1.6)	5(0.8)	0.226
Dopamine receptor agonist	5(0.7)	1(0.2)	0.231
Antiemetics	0(0.0)	0(0.0)	-

***p < 0.001 **p < 0.01 *p < 0.05

^a Values are expressed as number (%) or median (interquartile range)

Age, body mass index, and the total number of drugs were analyzed using the Wilcoxon rank-sum test

The other one was analyzed χ² test or the Fisher’s exact test

A total number of drugs of 0 refers to patients whose only prescription met the exclusion criterion for drug counting (topical or acute prescription drugs used within 7 d)

PIMs; Potentially inappropriate medications

Relevant factors for oral frailty

Before multivariate logistic regression analysis, correlation coefficients were checked for seven significant items in the univariate analysis and clinically important items (age, sex, frailty, number of natural teeth, total number of drugs, polypharmacy, and benzodiazepine)(Table 2). There was a strong positive correlation between total number of drugs and polypharmacy (ρ = 0.833). There was also a weak correlation between total number of drugs and benzodiazepines (ρ = 0.302). Therefore only polypharmacy not total number of drugs used in the multivariate logistic regression analysis, because there was a correlation between polypharmacy and total number of drugs, and between total number of drugs and benzodiazepines.

Table 2.

Spearman correlation coefficients between factors extracted as candidates for oral frailty relevant factors

Multivariate logistic regression analysis was conducted with oral frailty as the dependent variable and age, sex, frailty status, number of natural teeth (fewer than 20), total number of drugs, polypharmacy, and benzodiazepine use as explanatory variables. The results showed that frailty, number of natural teeth (fewer than 20), and benzodiazepine use were significantly associated with oral frailty (Fig. 1) (p < 0.001, p < 0.001, and p = 0.038, respectively). The result of the Hosmer-Lemeshow test was p = 0.366.

Fig. 1.

Multivariable logistic regression analysis for oral frailty relevant factor identification. ***p < 0.001 **p < 0.01 *p < 0.05. OR: Odds ratio, CI: Confidence interval. Adjusted for frailty, age, sex, number of natural teeth, total number of drugs, polypharmacy, and benzodiazepine use

The result of the association between the number of relevant factors and oral frailty was in Fig. 2. The rates of oral frailty were 50.1% for those with only one of the three relevant factors, 95.8% for those with two relevant factors, and 100% for those with all three relevant factors. Patients with relevant factors had significantly higher rates of oral frailty than those without relevant factors.

Fig. 2.

The association between the number of relevant factors and oral frailty. ***p < 0.001

Discussion

In this cross-sectional study of pharmacy visitors, we analyzed the associations among oral frailty, drug use, and other patient background characteristics, identifying relevant factors using information from patient questionnaires and pharmacy medication history records. Our results suggest that frailty, having fewer than 20 natural teeth, and the use of benzodiazepines may be relevant factors for oral frailty. Our results will help pharmacists identify patients with oral frailty at an early stage and provide proactive intervention and support, including appropriate patient education and recommendations for dental care.

The proportion of patients in the oral frailty group was 54.9% of the eligible participants in the present study. In a previous Japanese study using the Oral Frailty Index-8 among patients with type 2 diabetes aged 75 years or older, the percentage of those with oral frailty was reported to be 53.2% [30]. Although the participant conditions and regions in both studies differed, a similar finding was revealed: more than half of the participants had oral frailty. In a previous Japanese study using the Frailty Screening Index among community residents aged 65 years and older, the prevalence of frailty was reported to be about 10% [31]. In the present study, the prevalence of frailty in the total population was 19.6%, higher than that reported in the previous study. A possible reason for this increased rate is that our study was conducted during the coronavirus disease 2019 (COVID-19) pandemic. Previous reports indicate that COVID-19 increased the rate of frailty transition [32]. Conversely, a previous Japanese study of community residents aged 65 years or older reported that 35% of patients had both oral frailty and frailty [13], higher than that reported in the present study (26.5%). In the previous study, oral frailty and frailty assessments included instrumental measures [13]. Therefore, differences in assessment methods for oral frailty and frailty between the previous and present studies may have been a factor in the difference in the proportion of patients with both frailty and oral frailty.

The present study suggested that frailty may be a relevant factor for oral frailty. This finding supports the results of previous studies [12–15]. As this was a cross-sectional study, determining a causal relationship between oral frailty and frailty was not possible; however, similar to previous studies, an association was observed, suggesting that frailty may increase the risk of oral frailty [12]. Future longitudinal studies should be conducted to elucidate the causal relationship between these conditions.

This study suggests that having fewer than 20 natural teeth may be a relevant factor for oral frailty. This finding also supports the results of previous studies [33–35]. Some reports have shown that having fewer than 20 natural teeth is a risk factor for frailty [12]. We infer that it is important to consider natural teeth because having ≥ 20 natural teeth makes chewing easier, thereby increasing the average life expectancy [5].

In our study, benzodiazepine use was identified as a relevant factor for oral frailty. Regarding the use of benzodiazepines, a study of pharmacy visitors in other regions of Japan found that the percentage of benzodiazepine users was 9.8% [19], while a population-based study in Japan found that the percentage was 11.4% [36]. With similar percentages of around 10–20%, benzodiazepines were the most common inappropriate drugs. Although there are no previous reports of an association between oral frailty and use of benzodiazepines, there is a report of an association between the chronic use of benzodiazepines and frailty in a previous foreign study of community-dwelling older adults [37]. Benzodiazepines are classified as anticholinergics. Muscarinic M3 receptors on salivary gland tuft cells bind to acetylcholine to produce saliva, but anticholinergics inhibit the action of acetylcholine, thus suppressing saliva secretion and causing thirst [38, 39]. In our study, patients who used benzodiazepines had significantly higher rates of dry mouth than those who did not use benzodiazepines (p = 0.001,data not shown). Thus, the use of benzodiazepines, which are anticholinergic drugs, may cause thirst and decreased salivary function, leading to oral frailty. It has also been reported that oral frailty leads to low nutrition, which in turn leads to mental frailty such as depression and cognitive decline [40]. Poor sleep quality has also been related as a risk factor for oral frailty [14]. It is also possible that oral frailty may have led to the need for benzodiazepine use. Therefore, in addition to the possibility that benzodiazepine use is associated with oral frailty, the conditions requiring the use of benzodiazepines (i.e., those requiring anti-anxiety and sleeping pills) may be associated with oral frailty. Pharmacists should pay close attention to patients who use benzodiazepines.

Patients with at least one relevant factor were more likely to have oral frailty, and most patients with two or more were oral frailty. In addition, about half of the oral frailty patients in this study did not see a dentist regularly (Supplementary figure). Therefore, our result suggested that pharmacists should be actively encouraged to see a dentist for patients with even one of the relevant factors when counseling in the pharmacy. We have undertaken the following initiatives related to oral frailty: we organized a seminar for pharmacists to learn the basics of oral diseases, and we developed the “Guidelines for Encouraging Oral Care Product Purchasers to Visit the Dentist” [41]. The guidelines include a list of expected dental symptoms and specific recommendations for dentist visits, tailored according to the types of oral care products sold at pharmacies. This initiative aimed to educate pharmacists so they could effectively advise customers to seek dental care when necessary. Additionally, we introduced an app at pharmacies that measures oral diadochokinesis, helping identify patients at high risk of oral frailty [42, 43]. For those flagged as high-risk, pharmacists recommend dental visits. We also provide nutritional consultations with dietitians for patients who may be at risk of malnutrition. Further collaboration between pharmacists and dentists, other healthcare providers is needed regarding oral frailty.

This study had some limitations. First, as this was a cross-sectional study, the causal relationship between the extracted relevant factors and oral frailty is unclear. The concept of oral frail is that oral frail leads to deterioration of mental status and quality of life [5]. It has also been reported that drug use, nutritional status, oral frailty, three aspects of frailty (physical frailty, mental frailty, and social frailty) interact with each other [40]. As people age and retire, reduced social interactions can lead to depression, often increasing the need for drugs, and less going out leads to less physical activity, which causes them to lose interest in themselves, leading to a decline in oral health literacy and oral frailty [5]. Additionally, it has also been highlighted that oral frailty can cause pronouncing clearly, chewing hard foods, or preventing spilling while eating, leading to social withdrawal, depression, increased drug use, and a reduction in physical activity as individuals avoid going out [5]. Therefore, mental status, quality of life, and oral frailty might be interrelated. Future longitudinal studies should be conducted to elucidate the causal relationship between relevant factors and oral frailty. Second, since our study focused on community-dwelling older adults in Japan, the generalizability of the findings to older populations in other countries remains uncertain. Cultural and lifestyle differences may influence the prevalence of oral frailty and frailty, as well as the usage patterns of drugs like benzodiazepines. Therefore, it is uncertain whether the results of our study can be directly applied to older adults in other countries. In a study using the Oral frailty index-8 in community older adults in China [15], oral frailty was 69%, and in a study using another checklist of oral frailty in community older adults in South Korea, it was 59% [44]. Although the participant conditions and regions in both studies differed, a similar finding to our study was revealed: more than half of the participants had oral frailty. Regarding frailty, the prevalence of frailty among community-dwelling older adults in Asia (Japan, Korea, China, India), Europe, and Latin America has been reported to be 10–30% [45, 46]. It has been pointed out that the prevalence may differ depending on factors such as country, culture, ethnicity, but specific details regarding how these differences influence the prevalence of frailty have not been extensively documented [45, 46]. Regarding the use of benzodiazepines, in population-based studies in other countries, Canada had 25.7% [47], France 26.9% [48], and Switzerland 11.2% [49], with similar percentages of around 10–20%, and benzodiazepines were the most common inappropriate drugs in all countries. However, a previous study suggested that the use of benzodiazepines may be influenced by multiple factors, such as the healthcare system, physician practice patterns, and cultural aspects [50]. Therefore, it will be important to assess these factors and confirm the situation in other countries in future studies. Third, participation was voluntary, which may have caused a selection bias. The participants were healthy enough to visit the pharmacy and may have been interested in the topic. A previous study has revealed that lack of knowledge about oral frailty is a risk factor for oral frailty [51]. Forth, we did not measure the height and weight of each patient, so height and weight were self-reported by the patients and may have been inaccuratet. There were 23 patients with extreme BMI values (< 5 kg/m² or > 100 kg/m²), and we excluded them. The reasons for this were as follows. For patients who had < 5 kg/m² BMI values, 3 patients entered 0 for height, 16 patients entered 0 for weight, and 2 patients entered height in mm instead of cm. For patients who had > 100 kg/m² BMI values, 2 patients entered height and weight in reverse. This is because the purpose of this study was to easily identify patients with possible oral frailty at pharmacies and encourage patients who do not regularly visit the dentist to do so. Measurements require more time from patients and pharmacies than self-reported. Considering the age of the subjects, there is a possibility of potential bias. Previous studies have shown an association between BMI and poor oral function in the older people [52]. However, previous studies have shown that the average BMI of people aged 65 and over in Japan is 23.2 kg/m² [53], and since the values obtained in this study are consistent, it is possible that the subjects’ self-reports were not too far. Moreover, previous studies of community-dwelling older adults Japanese demonstrated a strong correlation between self-reported and measured BMI values, indicating that self-reported BMI is sufficiently accurate for use in epidemiological research [54, 55]. Hence, using self-reported BMI data in this study is considered appropriate. However, prior research has highlighted that the accuracy of self-reported BMI tends to decline with increasing age, lower education levels, and lower income among older adults [55, 56]. Additionally, studies on adults not older adults have suggested that the accuracy of self-reported BMI may vary depending on ethnicity and cultural factors [56]. Therefore, direct weight and height measurements may be necessary when conducting similar studies in different populations or regions. Fifth, we were unable to obtain information on the use of non-prescribed over-the-counter drugs, comorbidities and nutritional status. Hence, they could not be included in the drug analysis. Polypharmacy was not extracted as a relevant factor associated with oral frailty in the multivariate analysis, although significant differences were found in the univariate analysis. Studies examining the association between polypharmacy and oral frailty used comorbidities and nutritional status as covariates [40]. In our study, we were able to obtain information on the types of drugs more abundantly than in previous studies because examined in pharmacies. Future analyses should include detailed information on patient drug use, comorbidities and nutrition status. Sixth, several methods are available for oral frailty and frailty assessments. To assess oral frailty, we used the Oral Frailty Index-8, which is commonly used in Japan [22, 23]. It is widely used in Japan, but there are as many previous studies in China as in Japan. Other checklists exist, such as the Oral and Maxillofacial Frailty Index (developed in 2020 and is used in South Korea and India) and the Oral Frailty Five-Item Checklist (developed in Japan, but require a dentist’s consultation) [31, 57, 58]. The concept of oral frailty was introduced in Japan in 2013 and has since spread to other countries [5, 59, 60], although at this time, studies using these checklists were only used for Asians. However, previous studies on oral frailty have been conducted outside of Asia, they did not require cultural adaption. Therefore, further studies in other regions are needed in the future. To assess frailty, we used the Frailty Screening Index, which is also commonly used in Japan [24]. Other tools exist [4, 61–63], and future studies using these tools are required.

Conclusions

The results of this cross-sectional study of Japanese pharmacy visitors indicated that more than half of the patients had oral frailty and that the presence of frailty, having fewer than 20 natural teeth, and the use of benzodiazepines may be important screening indicators for oral frailty. These findings will provide evidence for community pharmacists to provide appropriate patient education and recommendations for dental consultation and will assist in community health care coordination.

Electronic supplementary material

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Abbreviations

BMI

Body Mass Index

PIM

Potentially Inappropriate Medication

Author contributions

Conceptualization: AMM, MT, YMo, SE, SK, KS, TT, YS, and YMa; Data curation: MT, SE, and SK; Formal analysis: AMM and MT; Investigation: MT, SE, and SK; Methodology: AMM, MT, TT, YS, and YMa; Project administration: TT and YMa; Software: AMM and MT; Supervision: YMo, TT, YS, and YMa; Validation: AMM and YMa; Visualization: AMM and MT; Roles/Writing–original draft: AMM and MT; Writing–review and editing: YMo, SE, SK, KS, TT, YS, and YMa.

Funding

This work was supported by Statistics Professors Training Programs (The Ministry of Education, Culture, Sports, Science and Technology (MEXT) Grant). The funding source had no involvement in the interpretation of data, writing of the report, and the decision to submit the article for publication.

Data availability

The datasets used and analyzed in the current study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

This study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethical Review Committee of Tokyo University of Science (Approval No. of Tokyo University of Science: 20024).

Informed consent

We conducted the study after obtaining informed consent from the patients.

Consent for publication

Not applicable.

Clinical trial number

Not applicable.

Competing interests

The authors declare no competing interests.