I.-C. Lee1, S.-F. Weng1, P.-S. Ho2
1. Department of Healthcare Administration and Medical Informatics, Kaohsiung Medical University, Kaohsiung, Taiwan; 2. Department of Oral Hygiene, Kaohsiung Medical University, Kaohsiung, Taiwan.
Corresponding Author: Pei-Shan Ho, Department of Oral Hygiene, Kaohsiung Medical University, Kaohsiung, Taiwan, 100,Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, Email: email@example.com, Tel: 886-7-3121101 ext.2159,
J Aging Res Clin Practice 2018;7:85-90
Published online May 24, 2018, http://dx.doi.org/10.14283/jarcp.2018.16
Objective: This study investigates whether the loss of natural teeth associate with elderly frailty, as well as their connection with quality of life. Design: This study collected data from January 2012 to April 2013, and the subjects were the elderly over the age of 65 living in community. Setting: Loss of natural teeth and frailty are common issues in elderly and it is noteworthy to address these issues while the investigation of healthy ageing. Participants: The research included 543 elderly people over the age of 65. Measurements: The face-to-face interviews with a structured questionnaire were performed. Results: Elderly people with no natural teeth are more likely to become frail (OR=1.87); the relationship between frailty and quality of life is more significant. After adjusting for all the independent variables, results showed that frailty in elderly leads to poorer quality of life, and oral health status is not correlated with quality of life (P>0.05). The remain of natural teeth is correlated with occurrence of frailty in the elderly. Conclusions: Frailty has a significant and strong influence on oral health-related quality of life. For the elderly, frailty shall be early diagnosed to ensure provision of proper preventive health care.
Key words: Elderly, frailty, loss of natural teeth, OHIP.
At present, various countries all around the world are facing the increase of elderly population, and the problem of ageing population structure has been increasingly severe. As of the end of 2012, the proportion of the elderly over the age of 65 in total population in the countries in the Europe and the U.S. was as follows: U.S. (13.7%), U.K. (17.0%), Germany (20.7%), Sweden (19.1%), and Finland (18.8%); and that in Asia is: Japan (24.1%), Korea (11.8%), and Taiwan (11.2%) (1). Among all of the above countries, the speed of population ageing in Taiwan has been considered as the top 1, and Ageing Index has also rapidly increased 32% in 10 years. The problems caused by elderly population certainly will become a trend that cannot be ignored in the society in Taiwan.
Many studies indicated that, the occurrence of loss of natural teeth in the elderly is very common, and 30-40% of the elderly are edentulous (2-4).During food intake, edentulous people tend to experience bradymasesis or fail to chew carefully and swallow slowly, which leads to malnutrition or diseases of digestive system (5-9). After a long period of time, their overall health functions will also be worsened (10-12), and their oral health-related quality of life will be lowered (13-16). In addition to oral health problems, in recent years, there has also been a research trend of investigation on elderly frailty. “Frailty” is not a disease, but merely an alert of loss of balance of health functions. Hamerman indicated that, as long as an elderly person who lives independently experiences the symptoms of frailty, his/her risk of death will be multiplied (17). Many studies found that, the proportion of the elderly with frailty suffering from chronic illness is higher, their overall health functions are poorer (18-19). A consensus on diagnostic criteria for elderly frailty has not been reached. The indices and criteria proposed by Fried et al. are most frequently adopted by experts and scholars internationally (20). The 5 indices include unexpected weight loss (weight loss of 10 pounds within the past year), self-perceived fatigue, weakness, slow walking speed, and reduced physical activities.
In sum, loss of natural teeth and frailty are common health issues in elderly. The association of health problems and quality of life in elderly is also highly focused in research (21-23). Among various assessments of oral health-related quality of life (OHRQoL), Oral Health Impact Profile (OHIP) developed by Slade and Spencer is the most popular evaluation within the field of dentistry research (24). The evaluation content includes the questions asking the subjects whether dental problems, oral problems or dentures affect their activities of daily living, as well as the questions on perceived level of distress. However, in order to increase the convenience and accuracy of clinical evaluation, subsequent researchers continuously developed shortened versions of evaluation tools, such as OHIP-14 and OHIP-EDENT (25-26). OHIP-14 is the short version (14-item) of original OHIP (49-item). OHIP-EDENT is based on OHIP and chooses appropriate questionnaire items for edentulous people, with a total of 19 items.
Frailty is the emerging trend of health issues. The literatures of whether the frailty associates with oral health status or whether the frailty affects oral health-related quality of life still remains limited. Therefore, the main purpose of this study is to investigate the correlation among loss of natural teeth, frailty, and oral health-related quality of life (OHRQoL) and provide the research results as reference for promotion of elderly oral health and planning of healthy ageing policies.
Material and Methods
Healthy ageing means to extend the life of being independent and to decrease the probability of being dysfunction and relying on others in elderly. The elderly aged over 65 years and walk independently, with or without cane, were enrolled as targeted subjects; whereas the elderly with diagnosed dementia were excluded. This study collected data from January 2012 to April 2013, and the subjects were the elderly over the age of 65 in San-Ming district of Kaohsiung City. This study selected the places where the elderly usually gather to engage in activities, such as parks and community activity centers. It is hoped to screen the high risk individuals from health elderly population. Researchers recruited the targeted subjects from the locations mentioned above to obtain their health-related information. The researchers who had received the training of questionnaire interviews performed face-to-face interviews with the elderly individually. The inter-rater agreement of these results reaches 94%. After the interviews, the researchers measured the subjects’ objective data, such as walking speed and grip strength. Under certain conditions, the questionnaire might be completed by interviewers based on subjective responses of elderly who have low vision and cannot fill out the forms independently. This study enrolled a total of 543 subjects. This study was approved by the Institutional Review Board of Kaohsiung Medical University Chung-Ho Memorial Hospital (KMUH-IRB-20120196). The study design, methodological procedure and administrative protocol were carried out in « accordance » with the approved guidelines. Informed consent was obtained from all subjects prior to data collection.
This study used a structured questionnaire to perform interviews. There are 135 items which derived from many validated assessments (e.g., ADL, and MNA) in this questionnaire to assess the health functional status in elderly. It takes 20 minutes to complete this questionnaire. According to the main research objectives, this study extracted some of the data for analysis. The detailed explanations on variables analyzed are given as follows:
(1) Demographic characteristics: age, gender, province of family register, educational background, economic status, and number of chronic diseases.
(2) Oral health status: this variable was mainly used to understand whether there were natural teeth in the mouths of the elderly. Due to the good accessibility of medical services in Taiwan and the welfare policy of “Dentures for the Elders Using Public Funding” provided by the government, elderly people with loss of natural teeth would usually obtain prosthetic treatment for free. The participants were categorized as dentulous group and edentulous group in this study. The dentulous group consists of the elderly who have natural teeth remained in the mouth, with unknown number of the natural teeth remained; whereas the edentulous group consists of the elderly who have no natural teeth remained in the mouth and these with complete denture.
(3) Frailty status: Fried (2001) used indices, such as weight loss, perceived fatigue, weakness, slow walking speed, and reduced physical activities to evaluate whether the elderly are frail. Because it is difficult to collect questionnaires on physical activities, this study used other 4 indices to understand the status of elderly frailty. In literatures, the indicators of frailty have not been standardized yet. Thus, the indicators of frailty that used in this study, described as follows, were modified from the indicators proposed by Fried et al. (2001).
This study asked the subjects about “whether he/she experienced weight loss within the last three months” and “whether they perceived fatigue within the last three months.” If the answers were “Yes,” the subjects experienced the signs of frailty. This study used electronic gripping device to measure the value of grip strength, in order to understand whether the elderly experienced the sign of weakness. Because the performance of grip strength varies with gender, this study divided the subjects into two groups: male subjects and female subjects. The 20% of subjects with the lowest value in each group were deemed weak subjects, namely, the high risk group of frailty. For the index of slow walking speed, this study asked the elderly to walk back and forth for 3 meters, and measured the time it took. Because the height of subjects might affect step size and waking speed, this study used the average height of all of the subjects as the baseline for division of groups. This study divided the elderly into two groups: tall and short groups. The 20% of subjects with the slowest walking speed were classified as frail subjects. The signs reflected by the said 4 indices were elderly frailty. This study summed up the total number of items of frailty. The subjects whose number of items of frailty ≥2 were deemed the subjects “with” frailty. These ways of discriminants are considerably valid that people with diagnosed frailty are comparatively unhealthy (27).
(4) Quality of life: This study used the short form version of OHIP-EDENT developed by Allen and Locker (2002) (Oral Health Impact Profile appropriate for use in edentulous patients) for measurement. This version can be used to understand the influence of general oral health problems on daily living. Moreover, some items were added to evaluate the influence of edentulousness on activities of daily living. The reliability and validity of testing of version in Chinese are very good as well(28). The higher the score was, the higher the perceived distress and influence of oral problems on daily living were and the poorer the quality of life was.
This study used the statistical software SPSS19.0 version to perform statistical analyses, and used Chi-square, t-test, and one-way ANOVA to understand the differences in demographic characteristics, frailty status, oral status, and quality of life (OHIP-EDENT). In addition, this study used logistic regression model to assess whether the oral health status associates with frailty; and used multiple linear regression model to investigate the influence of frailty status and oral status on quality of life.
Table 1 shows that compared with those in non-frail group, frail group has higher percentage of subjects over the age of 80 years (40.4% vs. 14.4%), higher percentage of subjects with illiteracy and with educational level under elementary school (70.3% v.s 54.5%), and higher percentage of edentulous subjects (44.1% v.s 24.0%)(P<0.05).
Note: This table is the results of Chi-square analysis
There are no relationship between the gender, native place with the scores of quality of life, whereas other variables demonstrate the significant difference on the scores of quality of life (P<0.05), as shown on Table 2.
Note: This table is the results of t-test, one-way ANOVA and Scheffes’ post-hoc method
Tables 3 and 4 investigated the correlation among oral status, frailty and quality of life. After demographic variables were adjusted, compared with subjects with natural teeth in their mouth, edentulous elderly were much easier to turn into being frail (OR=1.87). In the regression model of exploring quality of life and relevant factors, any signs of being frail in elderly correlates positively with the scores of quality of life, whereas no significant difference on scores of quality of life no matter any of natural teeth remains in elderly (Table 4). After all of the independent variables were adjusted, frail group of elderly has much poorer quality of life than those in non-frail group of elderly. This study compared the correlation between two variables, frailty and oral health status, and quality of life, and found that, the correlation between frailty and quality of life was stronger (β=0.21) and significant (P<0.05). Oral health status correlates much less with quality of life (β=0.05) and did not reach the significant level (P>0.05).
This study found that, age, province of family register, and oral status were correlated with the occurrence of frailty (Table3). Elderly with increased age might much easier become frailty. Literature(18,29)indicates that physical functions also decline day by day with the increase of age, and the elderly may easily experience symptoms of frailty, such as fatigue, weakness, and slow walking speed. Elderly with no natural teeth remained might much easier turn into being frailty. Some literature(6,30-31)show that elderly with poor oral health status may demonstrate malnutrition, weight loss, and frailty due to their poor chewing capability. The elderly whose province of family register is not Taiwan are also less likely to experience symptoms of frailty. This phenomenon is the same as ethnic factor abroad. In Chinese society, living styles and dietary culture of people vary with their province of family register, which may lead to the difference in health status (32).
The main objective of this study was to investigate the correlation among frailty, oral health status, and quality of life. The association of frailty and oral health status was previously mentioned. The frailty and oral health were served as variables within the regression model of quality of life scores to clarify their associations with quality of life. As results shown that the elderly with frailty have poor quality of life whereas the oral health status has not related with quality of life. Even though frailty and oral health problems are the common issues in elderly population, their impacts on quality of life is different. “Frailty” is only a health alert. In the field of clinical medicine, diagnostic criteria and treatment guidelines for signs of frailty have not been developed. Therefore, medical therapeutic intervention usually will not be immediately implemented for the symptoms of frailty in the elderly. The quality of life may get worse if individual’s frailty status does not improve (18, 33). In contrast, this study divided oral health status into two groups, edentulous subjects and dentulous subjects. Due to the development of current medical technology, dental materials have been gradually stabilized. Also, there is the welfare policy for funding the free denture placement of elderly in Taiwan, thus, most edentulous elderly may wear the whole set of removable denture. Therefore, the perceived distress and influence of oral problems in daily living were less significant. Compared with the strength of influence of frailty, the correlation between edentulousness and quality of life was weaker. Therefore, quality of life was not affected by it (14, 34).
In addition to frailty and oral health status, the results also demonstrated the difference in age, educational background, economic status, and the numbers of diagnosed chronic diseases would lead to the difference in score of OHIP-EDENT (Table 4). It is suggested taking the above variables into consideration in the future study for further investigation of oral-related quality of life. The associations of these variables and quality of life were synthesized as follows. The score increased with the increase of age, suggesting that, the subjects’ quality of life was poorer and they perceived increased distress in daily living due to oral health problems. In addition to the loss of natural teeth, other oral health-related problems increase with age, and lead to the gradual decline of quality of life (19, 35-36). People with better education may comprehend health-related knowledge better (37-39), leads to the oral health problems not affect their activities of daily living that much. The people with poorer economic status tend to experience economic barriers and fail to obtain sufficient medical care services. Thus, the daily living of these people might be disturbed by the oral health related problems, then further affects their quality of life (35-36). The oral health status of people suffering from chronic illness may become poorer due to side effects of drugs or the influence of illness(37,40). Therefore, they will perceive distress in activities of daily living, which affects their quality of life.
The health care issues in elderly population are important and shall be addressed in the future. In order to slow down the speed of growth of medical expenses and enrich the quality of life, the concept of healthy ageing shall be globally promoted. It is highly important that clinical professionals can early detect the high risk elderly population. Frailty is the alert of unbalanced health functions. Although it is not deemed a disease, it will trigger a series of negative health outcomes and further affect oral health-related quality of life. Dentists and oral health care-related personnel shall devote themselves to the oral health treatments in order to maintain and improve the oral health-related quality of life in elderly population. The extra attention shall also be paid on whether the elderly experience symptoms of frailty. This could be beneficial to the early detection of these elderly with frailty. Furthermore, it is hope that the proper preventive cares and health promotion services can be provided in advance to ensure the achievement of healthy ageing.
Ethics approval: This study was approved by the Institutional Review Board of Kaohsiung Medical University Chung-Ho Memorial Hospital (KMUH-IRB-20120196). The study design, methodological procedure and administrative protocol were carried out in accordance with the ethical approved guidelines. Informed consent was obtained from all subjects prior to data collection.
Availability of data and materials: All datasets on which the conclusions of the manuscript presented in the main paper.
Competing interests: The authors declare no conflict of interest.
Funding: Not applicable.
Authors’ contributions: I-Chen Lee defined the research theme and mainly contributed to study design, literature synthesis, data collection, statistical analysis, manuscript-writing and formation; Shih-Feng Weng mainly contributed to study design, statistical analysis, manuscript-writing and formation; served as consultants in advanced statistical analysis, data interpretation ; Pei-Shan Ho served as consultants in data interpretation and manuscript refinement. All authors read and approved the final version of the manuscript submitted for publication.
Acknowledgements: Sincere appreciation will be given to all individuals who participate in this study.
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