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Biomedical subjects

J L Leake

Publications and source records attributed to J L Leake.

At least 37 records · Page 2Linked to original sources
PubMed1996

Economic issues in the development and use of practice guidelines: an application to resource allocation in dentistry.

In this paper, the extent to which practice guidelines using cost-effectiveness data can be used to inform programme decisions is analysed. In particular it is shown that guidelines aimed at informing individual patient-provider decisions are unable to reflect the economic concepts that are required to inform public decisions concerned with making best (i.e., most productive) use of the resources available to serve defined populations. The research on which practice guidelines are based represents an important but incomplete source of information for taking decisions about which clients to serve, with which services, and when in the disease process, in the context of provision of services to groups or populations. Moreover, the inappropriate use of 'individually focused' guidelines to inform 'collectively-focused' decisions can lead to more harm than good. An alternative approach for dealing with the difficult choices faced by decision makers involved in public programmes is identified. An illustration of the proposed approach is presented concerning the provision of pit and fissure sealants to children served by a public health clinic.

Child↗
PubMed1996

Report on the RCDS-CDHSRU workshop on developing clinical guidelines/standards of practice.

Investigators from the Community Dental Health Services Research Unit (CDHSRU) held a workshop to test a model for developing clinical guidelines/standards of practice, which are required under the Regulated Health Professions Legislation. Forty-two individuals from Ontario and Canada, including dentists, representatives of the public, and professionals, participated in the three-day workshop, held under the auspices of the quality assurance committee of the Royal College of Dental Surgeons of Ontario (RCDS). Through direct experience, workshop participants sought to learn each of the steps, as defined by the literature, involved in clinical guideline development. Ultimately, they hoped to recommend steps for RCDS to follow in developing standards of practice. To ensure that a realistic and valid model emerged from the workshop, a real topic, namely the management of smooth surface enamel lesions in permanent teeth, was used to develop and test clinical guidelines. Prior to the workshop, participants were sent literature on one of five aspects of the topic, as well as papers describing the methodology of critically appraising the literature, and partially-completed templates outlining the basic steps to be followed. During the first evening and first morning of the workshop, participants listened to presentations on the development of clinical guidelines, the prevalence of smooth surface lesions, the role of economics in guideline development, and the necessary considerations in writing clinical guidelines. Under the leadership of trained facilitators, they then worked in small groups to write evidence-based recommendations and report them to the other workshop participants for feedback. Using this feedback, they returned to their groups to revise their recommendations and work on the workshop's overall recommendations to the RCDS. The day concluded in the evening, when the workshop facilitators and coordinators met to edit the groups' recommendations into a consistent format for presentation to all participants. On the second morning, the participants attended a plenary session to review the evidence-based recommendations developed by the groups, as well as their overall recommendations on the steps to be followed by the RCDS. Ultimately, workshop participants partially completed the templates and developed preliminary evidence-based recommendations on the management of enamel smooth-surface caries. Based on their experiences, they recommended a seven-step process for the future development of clinical practice guidelines/standards of practice in Ontario. These steps are recommendations only, and are not RCDS policy.

Canada↗
PubMed1996

The use of dental radiographs to estimate the probability of cavitation of carious interproximal lesions. Part I: Evidence from the literature.

It is generally recommended that a cavitated, carious lesion be present before an interproximal tooth surface is restored. These lesions often are not clinically visible, however, and must be diagnosed using dental radiographs. Radiographic results can underestimate and overestimate the size of a carious lesion. The purpose of this study was to review and graphically summarize studies that have investigated the relationship between the radiographic image and the presence of a cavitated lesion on the interproximal surfaces of permanent teeth. A search of the literature identified 13 studies, eight of which were suitable for inclusion in our summary. Using the positive and negative likelihood ratios from each study, a graphical summary was developed showing the probability of cavitation based on the radiographic test result and the dentist's pre-radiograph estimate of the probability of cavitation. This graph should allow dentists to more accurately inform their patients of the probability of a cavitated interproximal lesion being present or absent. As a further observation, our findings suggest that to avoid frequent false positive diagnoses, dentists should estimate the probability of cavitation to be at least 30 per cent before they prescribe radiographs for patients who visit them on a regular basis.

Bibliographies as Topic↗
PubMed1996

The use of dental radiographs to estimate the probability of cavitation of carious interproximal lesions. Part II: Two patient scenarios.

Diagnosis of a cavitated interproximal lesion is often not confirmed until the tooth is treated. Before treatment, clinicaians and patients are dealing with probabilities which can be estimated from clinical evidence, radiographic evidence, and information found in the dental literature. The probability of a diagnostic test result being correct is affected by the threshold of the test and the pretest probability of the disease in question, which varies with the prevalence of the disease. We illustrate how clinicians can inform themselves and their patients of the probability of a radiographic lesion being truly cavitated based on graphs that summarize the currently available evidence. Dentists who use these graphs can more accurately inform their patients who can then choose the course of care that best meets their individual needs.

Adolescent↗
PubMed1995

Estimation of procedure times in a publicly funded dental programme.

For the purposes of planning and evaluation, knowing the time-costs associated with each dental procedure carried out in a publicly funded dental programme is very helpful. This knowledge, along with the expected or known benefits, also allows researchers to assess the efficacy of a dental procedure. However, only a few estimates of dental procedure times exist in the literature, and most of these focus on restorative treatments. The North York Public Health Department operates a school-based public dental programme, where each dental procedure carried out by a dentist or hygienist is entered into a dental management information system database, along with the date of the procedure and the hours worked by the provider on that date. Using these data and multiple regression analyses it was possible to estimate the average time required to carry out the most common procedures in North York's dental programme. These estimates were found to be similar to estimates published in the dental literature and very similar to estimates of the Ontario Dental Association. Thus, this method of calculating procedure times appears valid and may be very useful to managers of public dental programmes and public dental health researchers.

Costs and Cost Analysis↗
PubMed1994

Social and functional impact of reduced posterior dental units in older adults.

The number of teeth needed to maintain adequate dental function in older adults is unknown. The purpose of this study was to examine the relationship between oral function and the number of opposing pairs of posterior teeth. We identified 338 subjects with complete anterior dentitions from an interview and examination survey of Ontario adults aged 50 and over; 261 had no partial denture and 77 had removable partial dentures (RPD). Oral function was measured using questions assessing chewing ability, mandibular function and socio-psychological impact. Subjects with no partial dentures were further allocated to five groups, based on their dental status: complete dental arch (n = 69); 5-7 functional units-pairs of opposing posterior teeth (n = 109); 3 or 4 functional units (n = 48) and 0-2 functional units (n = 35). Oral function problems increased with decreasing functional units being markedly more prevalent among the groups with 0-2 functional units. 34% of subjects in the 0-2 group reported one or more problems with chewing ability compared to 6-17% in the other groups (chi 2 P = 0.001 d.f. = 3). The 77 subjects who wore removable partial dentures, reported social and dental function at levels comparable to those with no dentures. From these results, there appears to be little socio-functional need to replace lost posterior teeth with a partial denture unit the person has fewer than, 3 posterior functional units. The low number of partial denture wearers limited our ability to detect a lasting benefit from RPD treatment.

Aged↗
PubMed1994

Technology assessment in dentistry.

Technology, in the context of dental health care, is a term that can encompass systems such as water fluoridation, clinical procedures such as sealants, or clinical protocols such as antibiotic coverage of patients with a history of heart surgery. Similarly, the term technology assessment (TA) describes a multidisciplinary, scientific process established to guide policy on the adoption and distribution of health technologies. While this process is already well established in medicine, it is just beginning in dentistry. As such, TA is still evolving in dental care in terms of methods and process. TA is required to guide the content of curriculum and standards of practice in a rapidly changing dental environment. It should precede the adoption or deletion of both technologies and of writing practice guidelines. TA makes it possible to shed inappropriate technologies or the inappropriate application of existing technologies, which may free resources to pay for improvements in the dental care we offer.

Canada↗
PubMed1993

Chemotherapy effects on hepatoblastoma. A histological study.

The histopathological features of hepatoblastoma in 17 patients treated with preoperative chemotherapy were compared with those in 11 patients not subjected to chemotherapy during the same 11-year period. Tumor necrosis was more extensive in patients receiving preoperative chemotherapy. Two tumors, however, were apparently unaffected by chemotherapy. There was no obvious correlation between the extent of necrosis and the number of courses of chemotherapy. There also seems to be no evidence of preferential ablation of a particular morphological type of tumor. The most notable feature in cases treated with chemotherapy was the extensive presence of osteoid. Osteoid was present in 36% of untreated cases, occupying < 5% of the surface area, compared with 82% in the treated group. In seven cases, osteoid occupied > 40% of the surface area. This finding raises speculation about the role of chemotherapy in the maturation of tumors that have an inherent ability to differentiate. A long-term study is needed to clarify the prognostic significance of mature heterologous elements in hepatoblastoma.

Adolescent↗
PubMed1993

Periodontal attachment loss in independently living older adults in Ontario, Canada.

This paper describes the periodontal disease experience of a community-dwelling population aged 50 years and older, living in four communities in Ontario, Canada. The periodontal status of this population was assessed using attachment loss and the extent and severity index. Attachment loss was measured at two sites on each tooth using a pressure-sensitive periodontal probe. Complete periodontal data were obtained on 624 subjects. The mean number of sites per subject was 37.9. In line with recent US studies, the diagnostic threshold for a diseased or previously diseased site was set at 2 mm of loss. The overall mean attachment loss was 2.95 mm, with 19.7 percent of subjects having an overall mean attachment loss of 4.00 mm or more. The proportion of sites examined with loss of attachment of 2 mm or more was 77 percent. The severity of disease, defined as the average distance between the base of the sulcus or pocket and a point 1.00 mm apical to the cemento-enamel junction in sites with loss of 2 mm or more was 2.44 mm. These data indicate that the extent and severity of disease in this population were greater than that reported by some recent studies in the US. Taken together, the results of these studies suggest that there is some variation in the periodontal disease experience of population subgroups across North America.

Aged↗
PubMed1993

Coronal and root decay experience in older adults in Ontario, Canada.

This paper describes the coronal and root caries experience of subjects aged 50 years and older living in four communities in Ontario, Canada. The data were obtained as part of a comprehensive epidemiologic study of the oral health and treatment needs of this population. Caries experience was defined as the number of decayed and filled coronal and root surfaces per subject. Of 907 subjects interviewed and clinically examined, 78.3 percent were dentate and retained a mean of 18.9 teeth. The mean number of coronal decayed and filled surfaces was 23.9; 95.6 percent of subjects had at least one coronal DFS. The mean number of decayed and filled root surfaces was 3.6; 70.9 percent had at least one root DFS. The percent D/DFS was 3.5 for coronal and 20.0 for root caries. In linear regression analysis the number of teeth, making regular preventive visits, being born in Canada, and educational status emerged as predictors of coronal DFS. Predictors of root DFS were the number of surfaces with recession, the number of coronal DFS, the number of teeth, age, sex, and smoking status. These variables accounted for 42 percent and 35 percent of the variance in the number of coronal and root DFS, respectively.

Aged↗
PubMed1993

Risk indicators and risk markers for periodontal disease experience in older adults living independently in Ontario, Canada.

This study examined risk indicators and risk markers for periodontal disease experience in 624 adults aged 50 years and over living independently in four communities in Ontario, Canada. The data were collected as part of the baseline phase of a longitudinal study of the oral health and treatment needs of this population. Periodontal disease experience was assessed in terms of attachment loss, measured at two sites on each remaining tooth. Bivariate and multivariate analyses were used to examine the relationship between a number of sociodemographic, general health, psychosocial, and oral health variables and three indicators of periodontal disease experience. These were: mean attachment loss, the proportion of sites examined with loss of 2 mm or more, and the probability of the subjects having severe disease, arbitrarily defined as a mean attachment loss in the upper 20th percentile of the distribution. Mean attachment loss was 2.95 mm (SD = 1.41 mm), and 76.6% of sites examined had loss of 2 mm or more. In bivariate analyses, the most consistent predictors of periodontal disease experience were: age, education, income, smoking, dental visiting, the number of remaining teeth, the number of decayed coronal surfaces, and the number of decayed root surfaces. In multivariate analyses, age, education, current smoking status, and the number of teeth had the most consistent independent effects. These data confirm the results of recent US studies indicating that periodontal disease experience is influenced by social and behavioral factors.

Age Factors↗
PubMed1993

A macroeconomic review of dentistry in the 1980s.

Dental expenditures in Canada receive less attention than other expenditures in the health care sector. Using publicly-available records, the authors have shown that the overall expenditures on dental care rose from $1.3 billion to $3.1 billion during the 1980s, or from $54.35 per person to $117.78 per person. Inflation and population growth would account for about 64 per cent of the increase, and the balance ($650 million) would therefore result from more services being provided. Per capita dental expenditures by province and territory show that people in the territory purchase the least care ($33.01 per person in 1989) and those in British Columbia purchase the most care ($145.54 per person in 1989). Even though some costs are not included in the data sources used for this paper, the direct costs of preventing and treating dental diseases ranks third among all diseases or conditions, exceeded only by the costs related to cardiovascular diseases and mental disorders.

Canada↗
PubMed1991

Utilization of dental services by older adults in four Ontario communities.

The elderly tend to use dental services less than most younger age groups. While the elderly's utilization rates may be rising, very low utilization by edentulous people depresses the overall rate for the group. We use data from the Ontario Study of the Oral Health of Older Adults to identify the variations in the use of dental services in the four study sites of Toronto, North York, Simcoe County and Sudbury and District. We reached 3,033 subjects by telephone and conducted dental examinations and a multi-item personal interview with 907 of them. The 907 subjects ranged in age from 50 to 87 years, 57 percent were female and two-thirds were born in Canada. Overall, 60.5 percent had seen a dentist or denturist in the previous year, but this was much lower among the edentulous (17 percent) when compared to the dentate (72 percent) (Chi-square test; p less than .0001). Of the 357 who did not visit a dentist or denturist in the previous year, nearly half (48 percent) felt they had nothing wrong and 20 percent reported they could not afford care. A high proportion (94 percent) of the edentulous reported visiting only for pain or trouble compared to 26 percent of the dentate (Chi-square test; p less than .0001). Using logistic regression, we found dental status (edentulous), community of residence (Sudbury), income (up to $20,000) and dental insurance coverage (none) were important factors in not making a dental visit in the last year. These same factors, plus education (elementary) were important where subjects reported visiting a dentist or denturist only when there was pain or trouble.

Aged↗