The Association between health-related quality ... - Wiley Online Library

Journal of Oral Rehabilitation 2009 36; 217–225

The Association between health-related quality of life and prosthetic status and prosthetic needs in Taiwanese adults H - C . K U O * , Y - H . Y A N G * , †, S - K . L A I ‡, S - F . Y A P * & P - S . H O *

*Faculty of Dental Hygiene, College of

Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, †Statistical Analysis Laboratory, Division of Clinical Research, Kaohsiung Medical University, Chung-Ho Memorial Hospital, Kaohsiung, Taiwan and ‡Division of Child and Adolescent Health, Department of Health, Bureau of Health Promotion, Taiwan, R.O.C

The objective of this study was to describe aspects of prosthetic statuses and needs and to evaluate their relationship with health-related quality of life in Taiwan. The study participants, aged 18 years and above, were recruited from a community survey, and each of the total 2469 participants received a dental examination and completed a questionnaire. Multivariable analysis was used to assess the adjusted means of healthrelated quality of life (SF-36) in both prosthetic status and need. The results showed that 12Æ6% of those aged 65 years and above were edentulous. The proportion of prosthetic need increased as age increased (39Æ7% to 61Æ3%). Multivariate analysis SUMMARY

Introduction Tooth loss is a common and irreversible oral health problem in the elderly population (1). Oral rehabilitation is generally performed to maintain basic oral function (2). Many studies have shown the benefit of prosthesis on recovering oral function, and hence the nutrient condition and general health (GH) can be improved (3–7). Previous studies on evaluating outcome of dental patients were primarily focussed on clinical measures of oral health. In recent period, the health-related quality of life from patients’ point of view has become more important. Gift et al. (8) reported that the health-related quality of life measures should include five general domains: opportunity ⁄ resilience, health perception, functional states, impairments ⁄ diseases and duration of life.

revealed that participants with ‘removable prosthesis’ had higher physical health scores than those with ‘non-removable prosthesis’. The scores of mental health measurement decreased in people with need for full prostheses in relation to people without need for any prosthesis. Therefore, fulfilling prosthetic needs is not only about recovering oral masticatory function, but also concerns improvement of both physical and mental healthrelated quality of life. KEYWORDS: quality of life, prosthetic status, prosthetic need, Short Form 36, oral health survey Accepted for publication 26 October 2008

Oral status and oral disease, such as tooth loss, number of remaining teeth, dry mouth and periodontal disease were previously shown to be related to healthrelated quality of life (9–15). A study from UK reported that the public perceived oral health as affecting their quality of life in physical, social and psychological life (16). People with more than 20 teeth had better subjective physical health than those with fewer than 20 teeth. In Japan (11), elderly persons (over 65 years old) and dentulous had better physical health than those who were edentulous (17). Tsakos et al. (18) found that there was a strong and consistent relationship between health-related quality of life and the presence of denture adaptation and retention problems among edentate elderly British people. Wearing prosthesis and edentulism are commonly associated with poor health-related quality of life and oral functional limitation (19). Therefore, assessing health-related

ª 2009 The Authors. Journal compilation ª 2009 Blackwell Publishing Ltd

doi: 10.1111/j.1365-2842.2008.01929.x

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H - C . K U O et al. quality of life should be considered as an important index in terms of oral health care. The Short Form 36 Health Survey (SF-36) is commonly used to measure GH status, including eight concepts with two main domains: psychology and physiology (18). The validation of Taiwanese version of SF-36 was translated and established in the 2001 Health Interview Survey, and the national norms at different ages were also determined (20). Unlike on prosthetic status, limited research has been carried out in evaluating the importance of prosthetic needs on health-related quality of life. Additionally, there was no large population study to support the importance of prosthetic status and prosthetic needs in health-related quality of life in Taiwan. While most studies have their focus on overall scores of the health-related quality of life, it is to be elaborated how the prosthetic statuses and needs related to the different aspects in health-related quality of life can be useful for improving patients’ well being. The objective of this study was to describe aspects of prosthetic statuses and needs and to evaluate the relationship with health-related quality of life. Furthermore, the extent of physical and mental health (MH) measurements of health-related quality of life on different prosthetic status and need is of special interest.

Materials and methods Study participants The study database consisted of two parts. The first part was to revisit study subjects who participated in the 2001 ‘Taiwan Areca quid Prevalence Survey, TAPS (21)’. This survey was a stratified multi-stage cluster sampling design using selection probability proportional to size. In the 2001 survey, residents of Taiwan aged 18 years and above were randomly selected. Residents from the military, hospitals, rehabilitation institutes, schools, dormitories and correctional facilities were excluded from the sampling frame. The stratification factor included geographical area, gender and age. The whole population was stratified into seven areas · two genders · four age groups. The geographical stratification was divided into seven strata, which included Taipei, northern, eastern, central and southern Taiwan, Kaohsiung-Ping Tung and aboriginal areas. In each geographical stratum, the age and gender characteristics

were divided into eight strata: four age groups (18– 34 years old, 35–49 years old, 50–64 years old and 65 years old or older) and two gender groups (male and female). The participants who agreed to participate in 2003 received dental examinations and personal interviews at home. There were 11723 participants in the 2001 survey of whom 60% agreed to the research team’s revisit for a dental examination. There were 4000 randomly chosen participants targeted in this study, only 1070 agreed. A major reason for the low response was because our study was conducted during the severe acute respiratory syndrome epidemic in Taiwan, and hence most subjects changed their mind about participating. Simultaneously, a second sample was collected according to the WHO Oral Health Survey guidelines (22). Organizations, such as businesses, companies or factory workers as well as readily accessible groups (e.g. at a market) were selected within sampling areas of the TAPS study. Thus, the final sample included 2670 participants, of whom 2469 persons received a dental examination and completed a questionnaire.

Clinical data collection All participants received a dental examination and personal interview. The guidelines of the ‘Oral Health Surveys – Basic Methods, 4th ed (22)’ were followed for the dental examinations with dental mirrors and WHO-approved ball-pointed periodontal probes under artificial light by specialized dentists. All participating dentists attended a pre-survey workshop to standardize the dental examination items. Only dentists with a kappa coefficient agreement of at least 0Æ70 were selected for this study. Examination items included ‘prosthetic need’ and ‘prosthetic status’. The kappa statistic was used to assess the inter examiner reproducibility. There were four items in prosthetic need involving: (i) no need: no need for prosthesis; (ii) one-unit need: need for one-unit prosthesis; (iii) multi-unit need: need for multi-unit prosthesis and need for a combination of one- and ⁄ or multi-unit prostheses and (iv) full prostheses need: need for full prostheses (replacement of all teeth). The prosthetic status included: (i) non-removable prosthesis: no prosthesis or fixed prosthesis; (ii) partially removable prosthesis: partial denture or both bridge(s) and partial denture(s) and (iii) fully removable prosthesis: fully removable denture.


PROSTHESIS ON HEALTH-RELATED QUALITY OF LIFE IN TAIWAN

Questionnaire Personal interviews were carried out by trained interviewers. Information on questionnaires included demographic information, habit of betel quid chewing, cigarette smoking and alcohol drinking, and the GH-related quality of life (SF-36). The SF-36 is a generic instrument developed for the Medical Outcomes Study. The eight concepts (subscales) and two summary scales of the SF-36 (23), scored on a scale of 0–100 are: physical function (PF), health problems resulting in limitations of physical activities, role-physical (RP), physical disability resulting in limitations of usual role activities, bodily pain (BP) and daily activities influenced by pain; GH (24), selfperception of GH; vitality (VT), overall energy level or lack thereof; role-emotional (RE), emotional problems resulting in limitations of usual role activities; MH, psychological well-being and stress; social function (SF), physical and emotional problems resulting in limitations of social activities; and the Physical Component Score (PCS) and the Mental Component Score (MCS). The validation of Taiwanese version of SF-36 was translated and established by Lu et al. (20) in the 2001 Health Interview Survey. The national norms at different ages were also reported (20).

Statistical analysis To adjust for the potential bias arising out of the data collection phase, all the statistical analyses were weighted according to the area ⁄ gender ⁄ age distribution of the 2004 demography registry, and carried out by SAS 9Æ1Æ2 (SAS Institute Inc., Cary, NC, USA) and SUDA AN 9Æ0 (Research Triangle Institute, Research Triangle Park, NC, USA). The estimated population proportions and mean were weighted according to the population structure. There were a total of 56 strata (seven areas · eight gender ⁄ age = 56). The population size of age 18 years and above in 2004 was first obtained for each strata (Ni, i = 1 to 56). Let the sample size of each strata be ni (i = 1 to 56), then the weight for each strata can be 56 56 P P Ni ; n ¼ ni and obtained by Wi ¼ Nnii Nn , where N ¼ i¼1

i¼1

the ‘i’ is one of the area ⁄ gender ⁄ age strata. SUDAAN software was used to implement the statistical computation for proportions and means, and 95% confidence intervals were used to show the precision of estimates. Chi-squared tests were used to investigate the association between gender and age groups (18–34, 35–49,

50–64, and 65+ years) with more than 20 teeth remaining, edentulous, prosthetic needs (no need, one-unit prosthesis need, multi-unit prostheses need, and full prostheses need) and prosthetic status (nonremovable prosthesis, partially removable prosthesis and fully removable prosthesis). Multivariate analyses were used to compute the health-related quality of life, assess the effect and adjusted means of prosthetic statuses and needs while adjusting for gender, age group, education, occupation and habits of betel quid chewing, cigarette smoking and alcohol drinking.

Results There were 2670 participants in this survey, of which 2469 persons received a dental examination and completed a questionnaire. For the whole population, the original sample size and weighted sample size for the area ⁄ age ⁄ gender distribution in 2004 of Taiwan Demography Regions is shown in Table 1. Table 2 shows the proportion of people with more than 20 teeth remaining and the proportion of edentulous people. In terms of more than 20 teeth remaining, males had a higher proportion than females (86Æ0% vs. 81Æ4%). The proportion also decreased as age increased (95Æ3%, 87Æ8%, 74Æ3%, 30Æ9%, P < 0Æ0001), which was a 43Æ3% difference between 50- and 64-year-old persons and persons aged more than 65 years. For the proportion of edentulous persons, females had a higher proportion than males (1Æ2% vs. Table 1. Comparison of actual sample size and weighted sample size (n = 2469)

Actual sample size

Weighted sample size

n

%

n

%

46Æ1 53Æ9

1249 1220

50Æ6 49Æ4

17Æ0 30Æ1 26Æ8 26Æ1

937 829 487 216

38Æ0 33Æ6 19Æ7 8Æ7

17Æ7 17Æ2

481 137

19Æ5 5Æ6

Gender Male 1139 Female 1330 Age group (years) 18–34 420 35–49 744 50–64 661 65+ 644 WHO Index age group (years) 35–44 437 65–74 423


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H - C . K U O et al. Table 2. Prevalence of 20 or more teeth remaining and edentulous in different gender and age groups

Actual sample size

Remain 20 teeth

Edentulous

% (95% CI)#

% (95% CI)#

Total Gender Male 1139 86Æ0 (83Æ5, Female 1330 81Æ4 (78Æ4, P-value 0Æ0138 Age group (years) 18–34 420 95Æ3 (91Æ5, 35–49 744 87Æ8 (84Æ5, 50–64 661 74Æ3 (69Æ4, 65+ 644 30Æ9 (24Æ8, P-value