Real-World Effectiveness of Nirmatrelvir/Ritonavir on Coronavirus Disease 2019-Associated Hospitalization Prevention: A Population-based Cohort Study in the Province of Quebec, Canada

BACKGROUND

Nirmatrelvir/ritonavir has shown to reduce COVID-19 hospitalization and death before Omicron, but updated real-world evidence studies are needed. This study aimed to assess whether nirmatrelvir/ritonavir reduces the risk of COVID-19-associated hospitalization among high-risk outpatients.

METHODS

A retrospective cohort study of outpatients with SARS-CoV-2 between March 15 and 15 October 2022, using data from the Quebec clinico-administrative databases. Outpatients treated with nirmatrelvir/ritonavir were compared with infected ones not receiving nirmatrelvir/ritonavir using propensity-score matching. Relative risk (RR) of COVID-19-associated hospitalization within 30 days was assessed using a Poisson regression.

RESULTS

A total of 8402 treated outpatients were matched to controls. Regardless of vaccination status, nirmatrelvir/ritonavir treatment was associated with a 69% reduced RR of hospitalization (RR: .31; 95% CI: .28; .36; number needed to treat [NNT] = 13). The effect was more pronounced in outpatients with incomplete primary vaccination (RR: .04; 95% CI: .03; .06; NNT = 8), while no benefit was found in those with a complete primary vaccination (RR: .93; 95% CI: .78; 1.08). Subgroups analysis among high-risk outpatients with a complete primary vaccination showed that nirmatrelvir/ritonavir treatment was associated with a significant decrease in the RR of hospitalization in severely immunocompromised outpatients (RR: .66; 95% CI: .50; .89; NNT = 16) and in high-risk outpatients aged ≥70 years (RR: .50; 95% CI: .34; .74; NNT = 10) when the last dose of the vaccine was received at least 6 months ago.

CONCLUSIONS

Nirmatrelvir/ritonavir reduces the risk of COVID-19-associated hospitalization among incompletely vaccinated high-risk outpatients and among some subgroups of completely vaccinated high-risk outpatients.

Healthcare utilization after a first hospitalization for COPD: a new approach of State Sequence Analysis based on the '6W' multidimensional model of care trajectories

Background

Published methods to describe and visualize Care Trajectories (CTs) as patterns of healthcare use are very sparse, often incomplete, and not intuitive for non-experts.

Our objectives are to propose a typology of CTs one year after a first hospitalization for Chronic Obstructive Pulmonary Disease (COPD), and describe CT types and compare patients’ characteristics for each CT type.

Methods

This is an observational cohort study extracted from Quebec’s medico-administrative data of patients aged 40 to 84 years hospitalized for COPD in 2013 (index date). The cohort included patients hospitalized for the first time over a 3-year period before the index date and who survived over the follow-up period. The CTs consisted of sequences of healthcare use (e.g. ED-hospital-home-GP-respiratory therapists, etc.) over a one-year period. The main variable was a CT typology, which was generated by a ‘tailored’ multidimensional State Sequence Analysis, based on the “6W” model of Care Trajectories. Three dimensions were considered: the care setting (“where”), the reason for consultation (“why”), and the speciality of care providers (“which”). Patients were grouped into specific CT types, which were compared in terms of care use attributes and patients’ characteristics using the usual descriptive statistics.

Results

The 2581 patients were grouped into five distinct and homogeneous CT types: Type 1 (n = 1351, 52.3%) and Type 2 (n = 748, 29.0%) with low healthcare and moderate healthcare use respectively; Type 3 (n = 216, 8.4%) with high healthcare use, mainly for respiratory reasons, with the highest number of urgent in-hospital days, seen by pulmonologists and respiratory therapists at primary care settings; Type 4 (n = 100, 3.9%) with high healthcare use, mainly cardiovascular, high ED visits, and mostly seen by nurses in community-based primary care; Type 5 (n = 166, 6.4%) with high healthcare use, high ED visits and non-urgent hospitalisations, and with consultations at outpatient clinics and primary care settings, mainly for other reasons than respiratory or cardiovascular. Patients in the 3 highest utilization CT types were older, and had more comorbidities and more severe condition at index hospitalization.

Conclusions

The proposed method allows for a better representation of the sequences of healthcare use in the real world, supporting data-driven decision making.

Utilisation et enjeux des données clinico-administratives dans le domaine de la santé mentale et de la dépendance

Les banques de données clinico-administratives sont des outils clés pour la prise de décision publique en santé. Pour soutenir la gestion des services, plusieurs banques sont disponibles s’intéressant aux besoins des populations et aux ressources disponibles, tout en intégrant des indicateurs de performance. Depuis les années 2000, des efforts considérables ont été menés afin de consolider les données et développer des outils visant à mieux surveiller l’état de santé des populations ou la performance du système sociosanitaire. Dans le cadre du congrès annuel de l’Association francophone pour le savoir (ACFAS), qui s’est tenu à l’Université McGill en 2017, un colloque a été organisé pour débattre de leur exploitation en santé mentale et en dépendance. Le colloque a intégré une discussion d’experts qui se sont entretenus afin d’identifier les principales banques clinico-administratives, l’ampleur de leur utilisation, leurs limites et les solutions à développer pour les optimiser afin de mieux soutenir la gestion des services. Cet article vise à résumer le contenu de ces discussions. Bien que les banques comportent des forces importantes, dont un potentiel élevé de généralisation de l’information, elles présentent des limites se rapportant surtout à leur capacité à répondre aux besoins, à des enjeux de qualité et de validation, ainsi que d’accessibilité. Diverses recommandations ont été émises pour améliorer leur gestion et optimiser leur impact, dont leur conservation et traitement dans un organisme autonome et hautement accessible, et un changement sociétal de culture favorisant l’évaluation de la performance afin d’améliorer les pratiques et de mieux monitorer les résultats de santé.

[Databank use and issues in mental health and addiction services]

Clinical-administrative databanks are a key tool in support of public health decision-making. A number of databanks are available relevant to population needs, resources available, as well as performance indicators. Since the 2000s, considerable efforts have been dedicated to the consolidation of findings and development of tools aimed at improving surveillance with respect to the health status of populations and performance of the social and healthcare system. At the annual congress of the Association francophone pour le savoir (ACFAS), held in 2017 at McGill University, a seminar was organized on the utilization of databanks in mental health and in addiction. This seminar featured an expert discussion on subjects related to: identification of the principal clinical-administrative databanks, the extent of their use, their limitations, and solutions aimed at optimizing the development of databanks to better support the management of services. This article summarizes the content of this seminar. While databanks entail important strengths, including great potential for the generalization of information, they also present limitations regarding their capacity to respond to needs, quality and validation issues, as well as accessibility. Various recommendations were proposed to improve the management of databanks and optimize their impact, including their centralization in a single, and highly accessible autonomous organism, and societal and cultural change favoring performance evaluation in the interest of improving practices and better monitoring health results.

Service utilization by hospitalized suicide attempters with schizophrenia or depression in Montreal

OBJECTIVE

The purpose of this study was to analyze patterns of mental health-related service utilization before and after hospitalization for attempting suicide.

METHODS

This retrospective cohort study included all persons 15 years or older with a clinical diagnosis of schizophrenia (N=195) or depression (N=330) hospitalized in Montreal, Quebec, from April 2003 to December 2004 for attempting suicide. Data on the publicly managed health and social services system were retrieved from the linked administrative databases of Montreal's Health and Social Services Agency (April 2002 to March 2005). Twelve-month preattempt service utilization profile, health care contacts three months pre- and postattempt, and predictors of postattempt service utilization were analyzed for two diagnostic groups (schizophrenia and depression).

RESULTS

Specialized outpatient care and hospital emergency departments were the services most used by both groups before and after attempting suicide. Use of hospital emergency services as a primary care service did not adequately ensure aftercare, whereas prior contact with services and concurrent substance use disorder predicted greater service utilization postattempt among men but not women.

CONCLUSIONS

The publicly managed health and social services system in Montreal seems to respond rather well to severe suicide attempts, including those by men with a concurrent substance use disorder known to be at high suicide risk. However, better coordination among hospital emergency departments, primary care, specialized mental health services, and addiction services is needed in order to enhance continuity of care.

[Portrait of the use of mental health services before and after a suicide attempt requiring hospitalization]

Health care systems play an important role in suicide prevention. Medical and administrative data allow analysis of patterns of mental health service use before and after hospitalization following a suicide attempt among Montreal residents diagnosed with schizophrenia or depression. Some results tend to show improvement in suicide prevention, especially among men with comorbid substance abuse disorders known to be particularly vulnerable. However, other observations are somewhat worrisome. The emergency room as an introduction to mental health services did not ensure adequate aftercare. Interventions are needed to improve access and coordination between different health care services.

Associations between school deprivation indices and oral health status

BACKGROUND

Despite an overall improvement in oral health status in several countries over the past decades, chronic oral diseases (COD) remain a public health problem, occurring mostly among children in the lower social strata. The use of publicly available indicators at the school level may be an optimal strategy to identify children at high risk of COD in order to organize oral health promotion and intervention in schools.

OBJECTIVE

To investigate whether school deprivation indices were associated with schoolchildren oral health status.

METHODS

This ecological study used a sample of 316 elementary public schools in the province of Quebec, Canada. Data from two sources were linked using school identifiers: (i) Two school deprivation indices (in deciles) from the Ministry of Education, a poverty index based on the low income cut-offs established by Statistics Canada and a socioeconomic environment index defined by the proportions of maternal under-schooling and of unemployed parents and (ii) Oral health outcomes from the Quebec Schoolchildren Oral Health Survey 1998-99 aggregated at the school level. These included proportions of children with dental caries and reporting oral pain. The relation between school deprivation indices and oral health outcomes was assessed with linear regression for dental caries experience and logistic regression for oral pain.

RESULTS

The mean DMF-S (mean number of decayed, missing and filled permanent teeth surfaces) by school was 0.7 (SD = 0.5); the average proportions of children with dental caries and reporting oral pain were 25.0% and 3.0%, respectively. The poverty index was not associated with oral health outcomes. For the socioeconomic environment index, dental caries experience was 6.9% higher when comparing schools in unfavourable socioeconomic environments to the most favourable ones [95% confidence interval (CI): 2.1, 11.7%]. Furthermore, the most deprived schools, as compared to least deprived ones, were almost three times as likely to have children reporting oral pain in the previous week.

CONCLUSION

The school socioeconomic environment index was associated with oral health outcomes, and should be studied for its potential usefulness in planning school-based oral health promotion and screening strategies.

Geographic information systems (GIS) in the health field: an opportunity to bridge the gap between researchers and administrators

This article starts by presenting some of the difficulties encountered by researchers and administrators in trying to work together. It then assesses the importance of the notion of territory in the planning and organization of health services. Last, the article presents the work achieved by the Agence de la santé de Montréal, where geographic information systems have contributed to bringing research and the field closer together.

Dental care pathway of Quebecers after a broken filling

OBJECTIVES

The objectives were to 1) describe the dental care pathway of adults after sustaining a broken filling, and particularly, the patient delay in seeking care as well as the continuity of care, and 2) identify factors associated with the decisions taken.

BASIC RESEARCH DESIGN

In 1998-99, 5,469 Quebec women aged 30 to 44 years completed a self-administered questionnaire in which they indicated whether they had experienced a dental problem in the previous 12 months. From then on, the questions identified the decisions they made during the process of consulting a dentist.

RESULTS

32.4% of the respondents had experienced a dental problem within the last 12 months. Among them, 38.0% reported a broken filling. 65.1% of those who identified a broken filling decided immediately to consult a dentist and 34.9% chose to wait and see. Patient delay was over one month in 44.0% of the cases. When asked by the dentist to come back in order to complete the treatment. 90.6% agreed, 3.2% decided to consult another dentist, and 6.21% chose not to consult. Logistic regression analyses show that patient delay was associated with low income, low degree of inconvenience (symptoms), low degree of perceived seriousness, and absence of a family dentist.

CONCLUSIONS

This study reveals important social disparities: after sustaining a broken filling, which remains an important problem in industrialised societies, patient delay, interruption of the dental care episode and extraction are more frequent in low-income groups. It also reveals that a wait-and-see attitude is more frequent than an interruption of the dental care episode after the first visit.

Inégalités sociales dans le recours aux soins dentaires

BACKGROUND

Despite excellent general health indices, Quebec is in a difficult situation concerning oral health: tooth loss remains at a high level in adults and reveals important social inequalities. The objective of this research was to show that dental health inequalities reflect inequalities in the demand for dental care.

METHODS

For the Dental Health Survey of Quebec 1998-1999, 9930 parents of children aged 5 to 8 years were randomly selected across Quebec and received a questionnaire at their home on the demand for dental care. Among them, 8430 adults completed and sent back the questionnaire (responses rate: 85%). After excluding edentulous persons, the sample was reduced to 6585 parents aged 30 to 44 years.

RESULTS

The majority of respondents (76.4% of women and 72.8% of men) visit the dentist in a preventive manner rather than wait until dental problems occur. However, our study shows important disparities: the proportion of preventive attenders increases as income increases. A multiple logistic regression model suggests that there are financial as well as cultural barriers in dental care access.

CONCLUSION

The proportion of preventive attenders is high in Quebec and allows practitioners to adopt a preventive management of dental caries. Social disparities are high however, and are associated with financial as well as cultural barriers that need to be reduced.

[Utilization of preventive dental services by recent immigrants in Quebec]

OBJECTIVES

Studies conducted in Canada show that recent immigrants tend to under-utilize preventive services provided by the health care system. The objective of our study was to learn whether this phenomenon also applies to dental care.

METHODS

Our sample was composed of 5,795 women who live in Quebec and are between 30 and 44 years old. These women filled out a self-administered questionnaire regarding their immigration status and their habits concerning dental visits. In our analyses, we compared the use of dental services of recent immigrants (10 years or less in Canada), long-term immigrants (more than 10 years), and non-immigrants (Canadians of origin).

RESULTS

55% of recent immigrants are preventive service users compared to 69% of long-term immigrants and 76% of non-immigrants. The financial barrier partly explains this result: immigrants often have a modest income and rarely benefit from dental coverage. However, having private dental insurance does not in itself explain the gap between these groups. This suggests that there is a cultural barrier in dental services access.

CONCLUSIONS

Under-use of preventive services by immigrants is not limited to the medical field, it extends to dental services as well. In order to facilitate immigrants' adaptation to the health system, we recommend that the government provide them with free dental services that respect their culture.

Shortcomings of health information on the Internet

Disseminating health and medical information on the Internet can improve knowledge transfer from health professionals to the population, and help individuals to maintain and improve their health. There are currently several medical information websites that directly target the general population with the aim of providing information about health problems, self-care and prevention. However, this new technology also hides several shortcomings, such as: (i) uneven quality of medical information available on the Internet; (ii) difficulties in finding, understanding and using this information; (iii) lack of access for the unconnected population; and (iv) the potential for harm and risks of over-consumption. To be able to overcome these dangers, it is important that public health practitioners and health professionals be involved in the design, dissemination and evaluation of Web-based health and medical information.

The dental care pathway of welfare recipients in Quebec

IN Quebec (Canada), the utilization of dental care services varies greatly from one social class to another: whereas the well-to-do visit the dentist often for check-ups, those most in need demonstrate a "wait-and-see" attitude. The objective of our research was to describe the dental care pathway of the underprivileged when confronted with symptoms, and to understand how this pathway might be interrupted and possibly lead to tooth extractions. We arranged 16 one-on-one interviews with adult Montrealers who had experienced a dental problem during the 12 months preceding the interview. These participants, 9 women and 7 men aged between 30 and 48, lived in great poverty: all were welfare recipients, and as such, enjoyed the benefits of a government programme that entitled them to free basic dental care. During the interviews, the interviewers asked the participants to describe their latest dental problem and their subsequent behaviour. The dental care pathway of our participants was characterized by a strategy of adapting to the symptoms. This process of adapting, which can last several months, is essentially an individual process in which the individuals often resort to self-medication to soothe their pain. They decide to visit a dentist when the pain is too great and self-medication is no longer effective. Once this decision is made, their dental care pathway may nevertheless be interrupted in two ways: first, in the failure to find a dentist, and second, later, in the failure to complete treatments that are not covered by the welfare program, such as endodontic treatment. The fragmented character of these dental care pathways refers us to two features of accessibility: financial accessibility and acceptability. With regard to financial accessibility, our study shows that the public coverage intended for welfare recipients presents major gaps. As for acceptability, our participants are strongly critical of the dental profession, and develop a culture of rejection of it.

Illicit drug use and injection practices among drug users on methadone and buprenorphine maintenance treatment in France

AIMS

To evaluate the associations between methadone and high-dose buprenorphine maintenance treatment and illicit drug use and injection among drug users in France.

DESIGN

A cross-sectional study. Data were gathered using a questionnaire administered containing closed-ended questions.

SETTING

Drug dependence clinics (DDC) and general practitioners' (GPs) offices in three French cities.

PARTICIPANTS

Drug users undergoing maintenance treatment with methadone (n = 197) and buprenorphine (n = 142).

MEASUREMENTS

Interviews covered the use of illicit drugs (heroin, cocaine or crack) and injection practices (illicit drugs and/or substitution drugs) during the last month, current treatment modalities, socio-demographic and health characteristics. Bivariate analysis and multivariate logistic regressions were conducted.

FINDINGS

Overall, 35.4% of respondents (34.5% in the methadone group, 36.6% in the buprenorphine group, P= 0.69) had used at least one illicit drug, 25.7% reported having injected drugs and 15.3% had injected the substitution drug. Injection was more common among buprenorphine-maintained individuals (40.1%) than among users on methadone (15.2%) (P < 0.01). Multivariate analyses indicate that the type of substitution drug (buprenorphine versus methadone) was not associated with illicit drug use (OR = 1.1; 95% CI = 0.7-1.8). In the buprenorphine group, injection was related independently to social situation, as measured by housing (unstable versus stable housing, OR = 4.3; 95% CI = 1.6-11.5), but this was not the case in the methadone group. The risk of injection increased with buprenorphine dosage (high/low dosage OR = 6.2; 95% CI = 2.0-19.7), but this association was not observed in the methadone group.

CONCLUSION

Further studies comparing the benefits of these two types of treatment should be carried out, taking outcomes such as physical health, mental health and social functioning into consideration.

Parental factors associated with regular use of dental services by second-year secondary school students in Quebec

The aim of this study was to identify the parental factors associated with regular use of dental services by second year secondary school students in Quebec. Data were collected in 1996-97, as part of a provincial survey on the dental health of Quebec students. A stratified probabilistic sample of 1,351 students, representative at the provincial level, was obtained. Data about frequency of use of dental services, parents' socio-economic characteristics, dental insurance (private and public) and parents' utilization of dental services were selected for this study. Half of the students used dental services regularly (i.e., once every 6 months). Multivariate analysis showed that the strongest parental factors associated with regular use were (in decreasing order of importance) the date of the mother's most recent dental visit, dental insurance, household income and the date of the father's most recent dental visit. After adjustment for the parents' socio-economic characteristics and the availability of dental insurance, students with one parent (particularly the mother) who had visited the dentist within the previous year had better odds of using dental services every 6 months, as recommended by professional standards.

[Knowledge and perceptions of adolescents regarding oral health]

OBJECTIVE

The objective of this study was to measure knowledge and perception related to oral health in Quebec children.

METHOD

For this study, a provincial sample of Quebec adolescents, 13 to 14 years old, was set up. Adolescents answered a 46-item questionnaire, specifically designed for the study. The questionnaire was completed by over 1,300 adolescents (participation rate = 53.0%).

RESULTS

The answers indicate that adolescents know the importance of toothbrushing and dental services utilization for dental caries prevention. However, their knowledge about dental sealant and fluoride is inadequate. Teenagers believe that they have a significant role to play in the prevention of dental diseases. However, many adolescents consider tooth loss to be a normal consequence of age. The majority of adolescents report their oral health as good. It is noted that dental aesthetics is a more significant factor for them than the quality of their teeth. Finally, dental care is a source of anxiety in one third of the adolescents.

CONCLUSION

The study of teenagers' knowledge and perceptions related to oral health shows that these elements are strongly influenced by environment, norm and culture. To improve dental health concerns in teenagers, public health policies should concentrate on these elements.

[Utilization of technology and communication technologies (TIC) in public health]

The development of information and communications technologies (ICT) and Internet offers public health practitioners new tools to fulfill their missions of monitoring public health, health promotion and disease prevention, and public health protection. In recent years, new applications and practices in public health using these technologies have emerged, particularly in the area of communication among practitioners and transmission of information to the population. This article aims to give an overall view of the use of ICT in public health and to discuss the impact of these technologies on public health practices. The discussion is centred around the implications of using these new technologies: implications with regard to the new possibilities provided by these technologies, but also with regard to the difficulties involved in their use as well as issues related to unequal access and ethics. Finally, the question of the evaluation of these technologies and of their impact on public health is discussed.

Dental caries in Quebec adults aged 35 to 44 years

BACKGROUND

The purpose of this study was to assess the prevalence of dental caries in Quebec adults aged 35 to 44.

METHODS

A stratified sample was used. The participation rate was 77% for the questionnaire and 44.5% for the oral examination. A total of 2,110 people were examined. The World Health Organization's caries criteria were used. Examiner agreement with gold standard dentist was excellent at the end of the nine-day training session (Kappa index > 0.8).

RESULTS

The level of caries experience is very high in Quebec adults aged 35 to 44. Almost half of dental surfaces (65 of 148) have been affected. These surfaces are mostly missing (39.3) or filled (23.9). However, there were 1.8 decayed surfaces in need of treatment per adult, and more than half the people (55.5%) had no untreated decayed surfaces. Almost three-quarters of decayed surfaces were present in only 14% of the people; lower family income and lower education are risk factors.

CONCLUSION

Comparison between Quebec and industrialized countries (United States, England and the Netherlands) shows that in adults 35 to 44, the mean number of decayed teeth is low (between 1.0 and 2.2) and the mean number of filled teeth is relatively similar (between 9.6 and 11.1); however, Quebec has a higher percentage than the United States of edentulous people. As well, in dentate adults, there are 1.6 times more missing teeth among Quebecers than among Americans.

Community periodontal index of treatment needs and prevalence of periodontal conditions

BACKGROUND/AIMS

In 1977, the World Health Organization (WHO) proposed a new index, the community periodontal index of treatment needs (CPITN) to evaluate the periodontal treatment needs of populations. The aim of this study is to compare different approaches of recording and presenting the CPITN.

METHODS

A sample of 2110 subjects aged 35-44 years were examined between September 1994 and July 1995, throughout the province of Quebec, Canada. For each tooth (3rd molars excluded), the presence of bleeding and calculus, the level of epithelial attachment, and the depth of periodontal pockets were measured. Periodontal pocket depths were measured from the edge of the free gingiva, at 2 sites (mesiovestibular and vestibular), as well as all around the tooth.

RESULTS

Only 8.5% of adults had at least one tooth with a 6 mm or deeper periodontal pocket when probing on 2 sites, whereas if probing is done all around the tooth, this percentage is 2.5x higher (21.4%). The partial recording of pocket depths (10 index teeth recommended by WHO, or 2 quadrants chosen at random) resulted in an underestimation of the prevalence of subjects with at least one tooth with a periodontal pocket (CPITN score 3 and 4). Among subjects with at least one tooth with a 6 mm or deeper periodontal pocket, 12% were not detected with the 10 index teeth recording, and 25% go undetected with the measure on 2 quadrants. Finally, using the % of subjects with periodontal pockets overestimates the prevalence of deep pockets compared with using sextants. Indeed, close to 30.0% of sextants have no treatment needs, whereas only 5.2% of subjects are in this category. Similarly, 7.7% of sextants have at least one tooth with a 6 mm or deeper periodontal pocket, yet there are 3x more subjects in this category (21.4%).

Comparison between the DMF indices and two alternative composite indicators of dental health

The DMFT and DMFS indices employed in the majority of oral epidemiological studies have several limitations. In response to this problem, Sheiham et al. (Community Dent Health 1987;4:407-14) proposed two alternative dental health indicators: the number of functioning teeth (hereafter referred to as FS-T) and tissue health (T-Health). Using data from an epidemiological study on the dental health status of adults aged 35-44 from Quebec (N=2110), this article compares the alternative indices with the conventional DMFT and DMFS indices. By comparing Pearson's correlation coefficient for the four indices in this study with the number of decayed, missing and filled surfaces, it is noted that the FS-T index bears the strongest correlation to the three variables. It is also the only index whose correlation coefficient is greater than 0.3 for each of the three DMFS components. A risk group was created for each index, composed of the 18% of people demonstrating the poorest index. The risk group's FS-T index results in an average of 4.3 decayed surfaces (compared with 2.6 for the DMFT), 92.7 missing surfaces (74.4 for the DMFT) and 9.0 filled surfaces (compared with 26.9 for the DMFT). Using linear regression analysis with each index as a dependent variable, and people's socio-demographic characteristics, regular use of dental services and perception of dental health as independent variables, it appears that the percentage of the explained variance (R2) is 21.2% for the FS-T index, 13.8% for the T-Health index, 12.3% for the DMFS index and only 7.6% for the DMFT index.

[Trends in the level of edentulism in Quebec between 1980 and 1993]

Level of edentulism is a good indicator of a populations' bucco-dental health. Thus, the evolution of this phenomena enables us to seek any modification of adults' bucco-dental health. The percentage of adults in Quebec aged 18 and over who are completely edentulous decreased from 26 per cent in 1980 to 20 per cent in 1993. During the same period, the percentage of adults aged 18 and over who are only partially edentulous decreased from 18 per cent to 13 per cent. We note on one hand that this decrease is more prominent among younger adults and among anglophones and on the other hand that income and education are more strongly associated with edentulism in 1993 than in 1980. In 1980, individuals with lower levels of education were three times more edentulous (partially or totally) than those with higher levels of education (73 per cent versus 25 per cent). In 1993, this ratio increased to six times (72 per cent versus 12 per cent). It appears, therefore, that while edentulism has generally decreased in Quebec, it is more concentrated among certain high risk groups.

Indicators of masticatory performance among elderly complete denture wearers

The literature on current techniques for evaluating the masticatory capacity leads to categorizing them into two groups: objective masticatory tests and questionnaires that evaluate the subject masticatory capacity. This study examines how a simple questionnaire on the reported capacity to chew certain food can predict the masticatory performance of edentulous elderly patients. The masticatory performance of 367 completely edentulous elderly persons was measured with the Swallowing Threshold Test Index and compared with their reported masticatory capacity previously measured with a questionnaire on the capacity of the individual to chew nine food items. A total of 47.4% of the individuals had a low masticatory performance. This problem was more frequent in women (51.7%) than in men (41.8%). In measuring the reported masticatory performance with seven of the nine food items listed in the questionnaire, this indicator predicted the masticatory performance with a sensitivity of 65.5% and a specificity of 81.9%. However, even though the measure of prosthesis retention/stability is related to the masticatory performance, it was not a good predictor.

[Use of dental services and the percentage of persons possessing private dental insurance in Québec]

The utilization of dental health services and the percentage of adult members of a private health dental insurance plan are generally lower in Quebec than in the other Canadian provinces. In this study, results of a telephone survey of a representative sample of Quebec adults aged 18 and over (N = 8,042) show that 58 per cent of interviewed individuals visited a dentist (53 per cent) or a denturologist (five per cent) during the 12 months preceeding the interview. A multivariate analysis indicates that the most strongly associated factors related to the utilization of dental health services are, in decreasing order, edentulousness, income and level of education. About one third (36 per cent) of those surveyed had dental insurance coverage. Age and income are the most strongly associated factors concerning the membership to a dental health insurance plan. Finally, among those with dental insurance coverage, 71 per cent had visited a dentist or a denturologist during the last 12 months compared to 51 per cent of those not insured.