Metodología para el trabajo experimental

In a pioneer study on the impacts of dental conditions in elderly people. Smith and Sheiham (1979) interviewed and clinically examined 254 people aged 65 years or older living at home in England (Nottinghamshire). The clinical oral condition of the subjects was generally poor, as shown by the high edentulousness rate (74%) and by the extremely low proportion of subjects with adequate dentures (10%). The interviews revealed a considerable volume of oral impacts, mainly related to eating. Difficulty chewing was reported by 30% of the subjects, while 12% reported that they had changed the composition of their meals and their methods of cooking, in order to be

able to chew food more easily. The social effects of this chewing inability were also striking, as 41% of the sample reported that they took long time to complete their meal and 9% felt uncomfortable eating in front of others. Furthermore, and apart from the eating-related impacts, 13% of the subjects felt embarrassment during social contacts.

In a paper attempting to critically examine the relationship between oral disease and quality of life, Ettinger (1987) argued for the necessity to investigate the effect of oral conditions on the social participation and functioning and psychological factors, such as self-esteem, on the grounds that they constitute important quality of life constructs. In a small, atypical sample of 46 elderly free-living subjects, over 75 years of age, the correlation between perceived oral health and self-esteem was moderate in strength, negative in direction and statistically significant (Berkey, Call and Loupe, 1985). Subjects with fewer dental problems perceived higher levels of self-esteem, in comparison to their more problematic counterparts. A closer examination revealed a much stronger significant correlation for the dentate elderly and a weaker insignificant result for the edentulous subjects, thus pointing to the pivotal role of the natural dentition. Nevertheless, the small sample size and the cross-sectional character of this study did not allow for definitive conclusions.

Although not directly indicating an oral impact, the subjective perception of xerostomia attracted considerable attention in the studies of older adults and is considered an important health problem in this age group. It was the most prevalent (18%) of 22 oral symptoms and complaints investigated among the 907 adults, aged 50 years or more, that participated in the baseline phase of the comprehensive Ontario Study of the Oral Health of Older Adults (Locker, 1993a). Furthermore, subjects with xerostomia were at an increased likelihood to be dissatisfied with their oral health and to report eating and communication difficulties, as well as other oral symptoms, such as unpleasant taste and pain from dentures. In a study of 600 elderly (65 years-old or older) subjects in Florida, the prevalence of xerostomia was 39% (Gilbert, Heft and Duncan, 1993). Its important effect in the everyday life of the subjects was reflected in their prevalent behavioural adaptations, in order to cope with the problem.

A broader perspective for the assessment of oral impacts was followed in the “Passport to Health” study, where the Geriatric Oral Health Assessment Index (GOHAI) was applied, through a telephone interview, in a sample 1755 elderly (aged 65 years or over), English speaking. Medicare participants with no terminal or dementing illness (Atchison and Dolan, 1990). The oral impacts in relation to eating were considerable in the previous 3 months, as 13% of the sample had “always” or “often” problems biting or chewing and 10% experienced frequent limitations in the kinds or amounts of food

eaten, while 9% always perceived discomfort while eating. Additionally, 10% were often worried or concerned and 6% were nervous or self-conscious about oral health problems, whereas 9% were never satisfied with the appearance of their teeth, gums and dentures. Further analysis indicated social status variation, because highly educated and richer subjects had higher GOHAI scores, indicating better health.

While cross-sectional studies could facilitate the assessment of oral impacts, the measurement of the benefit of dental care, in terms of improvement in the quality of life, needs a longitudinal design. In one of the few longitudinal studies in this area of research, Fiske, Gelbier and Watson (1990) used a sociodental measure of oral handicap before and, at different time intervals, after the provision of dental care, in order to monitor the perceived benefit of treatment in a group of 100 older adults, aged 65 years or over. The sample consisted of highly compromised subjects who demanded dental care from the Community Dental Service in United Kingdom and were predominantly edentulous (79%) and in need of prosthetic care. The sociodental measure covered the themes of function, comfort, self-image and social interaction. The subjects had a considerable burden of oral impacts during the initial examination, as 87% of the sample reported problems with social interaction, 68% with function, 51% with self-image and 46% with comfort. These high prevalences should be expected, as they referred to subjects seeking dental care, and not the general population. By 2 weeks after the provision of treatment, benefit from dental care was perceived by almost half of the sample, and it related mainly to the self-image and social interaction domains. By 2 months post-treatment, 70% of the sample were free from impacts and this improvement resulted in the minimisation of the oral impacts related to comfort. No significant further decline was observed between 2 and 6 months post-treatment, leaving almost one quarter of the sample with impacts. Consequently, despite the fact that the sociodental measure proved to be a useful tool in the assessment of the benefit of dental care, 32% of the people initially perceiving an impact in the function domain continued to do so after 6 months.

In one of the most comprehensive studies. Locker (1992) assessed the burden of oral disorders in a sample of independently-living older adults in Ontario, Canada, through the use of a combination of subjective measures related to oral disease and impacts. The assessment of impacts referred to the 907 subjects that participated in the baseline phase of a longitudinal epidemiological study of adults aged 50 years or older. Apart from the clinical oral examination, the assessment of chewing ability and oral pain, disability and handicap were assessed through a seven-item scale of the social and psychological impacts of oral conditions, one item addressing worry and concern due to oral health problems and three questions about satisfaction with oral health.

Overall, almost one fifth (19%) of the sample had high levels of worry about their oral health, around one third (31%) were dissatisfied with some aspects of their oral health status and more than one third (38%) perceived one or more social and psychological impacts related to oral conditions sometimes or more frequently. With respect to eating- related impacts, one in five reported that oral conditions prevented them from eating foods they would choose, while around 15% found that it took them longer to complete their meal and their enjoyment of food was limited by oral conditions. Additionally, 5% reported that they avoided eating with other people because of chewing problems. Of the impacts related to communication and social interaction, embarrassment from the appearance of their teeth and mouth was prevalent in 14% of the respondents, while almost 8% avoided laughing or smiling. Edentulous subjects had higher prevalence for all seven items, in comparison to their dentate counterparts, but the differences were significant for the oral impacts related to eating, but not also for those related to communication and social interaction. Apart from the variations between dentate and edentulous subjects, significant associations were also observed between oral impacts and various sociodemographic variables (income, age, education). Moreover, the effect of income remained significant, with low income groups experiencing higher levels of social and psychological impacts, even after controlling for clinical factors, chewing capacity and pain and other symptoms experience.

The estimation of the effect of teeth on the social, psychological and biological functioning and the overall quality of life was facilitated by the application of the Dental Impact Profile (DIP) in a representative sample of 1018 adults aged 65 years or older, independently-living in the five contiguous North Carolina counties and participating in the baseline phase of the Piedmont 65+ Dental Study (Strauss and Hunt, 1993). This study focused on the prevalence of the different items of DIP, while the investigation of racial variation in oral impacts was presented later (Strauss, 1996) and can be found in the relevant section of this review. Higher proportions of the sample opted for the positive, in comparison to the negative, responses regarding the effect of teeth and dentures for all DIP items, apart from the one related to breath. The most positive effects were reported for appearance and eating. Still, 30% of older adults perceived a negative effect of their teeth and dentures on chewing and biting, 25% on eating, around 20% on the choice of foods, the enjoyment of eating and comfort, followed by considerable negative effects on breath, appearance and speech. Even more striking, though, was the finding that more than three fourths of the sample reported that their teeth or dentures did not have any effect, neither positive nor negative, on their moods, weight, appetite, romantic relationships, success at work, attendance at activities, or kissing.

Locker and Slade (1993) used part of the sample of the baseline phase in the Ontario study of older adults, in order to test the validity and reliability of CHIP as an outcome measure of oral impacts and quality of life. After the validation process was successful, they further attempted to assess oral impacts by posting CHIP to the whole sample of the baseline phase of the study, but one year later. This methodological approach resulted in a reduction in sample size, as, from the initial 907 subjects, 699 returned completed questionnaires. One further possible limitation related to the one year gap between the clinical examination and the application of CHIP. Furthermore, the oral impacts outcome measure referred to the proportion of people experiencing impacts “fairly” or “very often”, and not to the weighted CHIP score. Nevertheless, this remained a key study that facilitated the application of a composite subjective oral health indicator in a randomly selected big sample.

The prevalence of oral impacts in this population was high. Functional limitation was experienced fairly or very often by 44%, pain by 21% and psychological discomfort and physical disability by 17% and 16% respectively. Psychological disability and handicap were each reported by 7%, while changes in social relationships were reported by very few people. This analysis by OHIP dimensions was also confirmed by the fact that the most prevalent frequently occurring individual items belonged to the functional limitation, pain and psychological discomfort dimensions (subscales). The single individual most prevalent item referred to food jcatching in teeth or dentures (36%), while a variety of items followed with prevalence just over 10%. The variation by sociodemographic variables was not extensive, as the only significant results related to the higher prevalence of pain for the relatively younger subjects (50-64 years-old) and to the higher prevalence of impacts related to handicap among women. The variation by dental attendance pattern among dentate subjects showed that respondents that failed to make regular use of dental services experienced higher levels of oral impacts in relation to psychological discomfort, psychological disability, physical disability and handicap. More substantial differences, though, were demonstrated between dentate and edentulous subjects. The edentulous respondents experienced proportionately more impacts than their dentate counterparts in relation to all seven OHIP dimensions, with statistical significance being achieved in all dimensions apart from functional limitation.

The OHIP was also used in the assessment of oral impacts in a survey of people aged 60 years or over in South Australia (Slade and Spencer, 1994b). The survey employed a meticulous methodological design and the sample consisted of 1217 respondents. Again, the oral impacts outcome measure was not the weighted OHIP score, but the proportion of people experiencing impacts “occasionally”, “fairly often” or “very

often”. This frequency threshold was lower than the one applied in the Ontario study (Locker and Slade, 1993) and, consequently, the comparability of the overall impacts prevalence between the two studies was relatively impaired. Nevertheless, this was not the case for individual items, where the fairly or very frequent prevalence could be obtained. A subsequent publication (Slade et al, 1996) assessed cross-cultural differences in oral impacts, as measured through OHIP, in Canada, South Australia and U.S.A. and is presented on the relevant section of this review. The analysis in this South Australia study (Slade and Spencer, 1994b) referred only to OHIP items, while a later publication presenting the OHIP dealt also with the analysis at the subscale level (Slade, 1997a: pp. 93-104).

The adoption of a lower frequency threshold for the determination of oral impacts has contributed to widespread prevalence. Overall, 92% of the dentate and 89% of the edentulous subjects experienced at least one OHIP impact occasionally, fairly or very often. In general, oral impacts were more prevalent in the edentulous than the dentate subjects, as shown by the significantly higher median and mean for the number of items reported (4 and 7.3 for the dentate and 6 and 8.5 for the edentulous respectively) (Slade and Spencer, 1994b). Analysis by OHIP subscales showed that the difference between edentulous and dentate subjects concentrated mainly on the physical disability and functional limitation subscales, though as the author stated this could be somehow expected, because the functional limitation, physical pain and physical disability subscales have one question each that applies to denture wearers only (Slade, 1997a: pp. 93-104). Like in Canada, the single most prevalent item was food catching. Again, while the most prevalent impacts did not represent very severe conditions, more profound impacts, such as those related to eating and chewing, were experienced fairly or very often by more than 10% of the edentulous and 5% of the dentate respondents. The respective prevalence of most OHIP items related to psychosocial well-being was lower than 5% for both dentate and edentulous. Apart from the different prevalence according to dental status, there was also significant variation in oral impacts by age, sex and, mainly, dental attendance pattern. Among edentulous respondents, females reported lower levels of impacts than males. A similar trend was observed among dentate subjects for older respondents and asymptomatic regular users of dental services (Slade and Spencer, 1994b).

2.4. RELATIONSHIP BETWEEN NORMATIVE AND SUBJECTIVE

M EASURES

Earlier studies investigating the relationship between clinical and subjective assessments of oral health and treatment needs concentrated mainly on the measurement of the

difference between normative and perceived assessments. More recently, and coinciding with the development of sociodental indicators, research has been more directed towards a detailed investigation of the relationship between subjective measures of oral health and impacts and clinical indicators of oral disease. Normative need measures have been substituted with more specific indicators of clinical characteristics, and the more general approach of perceived need has given way to refined and composite measures of oral impacts and oral health related quality of life. This review attempts to present both groups of studies, but, consistent with the aims of the thesis, focuses more on the latter.

In a study comparing different domains of need for dental care in poor elderly people. Banting (1971) demonstrated differences between normative and perceived need, with higher prevalence for the former. In another study of 254 predominantly edentulous (74%) elderly people living at home, the extremely prevalent perceived notion of handicap was not significantly related to the normative assessment of the oral health status, as demonstrated by the fact that 78% of the subjects were clinically diagnosed as in need of dental treatment, but only 42% perceived such needs (Smith and Sheiham, 1980). Branch, Antczack and Statson (1986) reviewed previous studies and estimated that 70% of older adults required some kind of dental treatment, but perceived need referred to only 25-40%. They further interviewed 776 elderly people aged over 70 years and showed that 37% of them had perceived dental treatment needs, but they failed to provide a normative need estimation, in order to allow for comparisons.

The normative-perceived treatment need discrepancy was also demonstrated in a study of 405 dentate adults aged 65 years or older in Quebec, where while almost the entire sample (96%) needed treatment, a significantly lower proportion (58%) reported experiencing dental problems (Brodeur et al, 1988). Similarly, among 293 older adults (60-years-old or over) referred to a Community Care Centre in South London, 82% were in normative need, 76% would have benefited from receiving dental care, but only 53% reported subjective need (Diu and Gelbier, 1989). Clearly, the largest amount of need related to replacement of unsatisfactory dentures. Manne and Mehra (1983) evaluated the difference between normative and subjective assessment of dentures in a small sample of denture wearers aged 60 years or over and found that it was not related to clinical evaluation nor to psychological factors, as there was a high proportion of subjects unaware of denture inadequacies and dissatisfied subjects wore technically superior dentures in comparison to satisfied respondents. In accordance to that, one fifth of those normatively assessed as in denture-related need in a sample of people aged 55 years or older, living in Camberwell in South London, did not perceive it (Taylor et al, 1994).

The investigation of different types of dental treatment needs in a sample of 1275 adults from different ages (25, 35, 50 and 65 years-old) in Finland reinforced the gap between normative and perceived assessments (Tervonen and Knuuttila, 1988). 23% needed, but only 14% wanted to replace missing teeth. Dentures were clinically non-acceptable in 64% and subjectively in 42% of denture wearers. Furthermore, normative restorative need referred to 80% and perceived need to 70% of the dentate subjects, while periodontal treatment need was normatively measured in 38% of the subjects with at least one dentate sextant, but perceived by only 20%.

A more detailed study aimed to explore the relationship between important clinical indices, like the number of decayed, missing and filled teeth and the presence of deep pockets, and perceived oral health status (Reisine and Bailit, 1980). Overall, 65% rated their oral health at least as “good” and only 8% as “poor”. The association of perceived oral health status with the number of filled teeth failed to reach statistical significance, while the respective associations with the numbers of decayed teeth, missing teeth and presence of deep pockets were significant, but weak. Furthermore, the correspondence between the clinical and the subjective indicators was of limited relevance, as 40% of the subjects with 15 or more missing teeth or with deep pockets and 25% of those with

10 or more decayed teeth rated their oral health as “good” or “excellent”.

Drake, Beck and Strauss (1990) examined the accuracy of oral self-perceptions and perceived dental treatment needs in over 800 dentate elderly subjects from the Piedmont 65+ Dental Study questionnaire, stratified by race. Perceived need considerably underestimated normative need in both White and Black subjects, though the differences were smaller among White participants. More specifically, among Black participants with no perceived need, half required restorative treatment, one third had deep periodontal pockets and one fourth required extractions, while among White subjects without perceived need, one fifth needed restorative care. Despite the gap between normative and perceived need in both strata, their self-perceptions of oral