Systematic review with meta-analysis: placebo rates in induction and maintenance trials of Crohn's disease

BACKGROUND

Minimising placebo response is essential for drug development.

AIM

To conduct a meta-analysis to determine placebo response and remission rates in trials and identify the factors affecting these rates.

METHODS

MEDLINE, EMBASE and CENTRAL were searched from inception to April 2014 for placebo-controlled trials of pharmacological interventions for Crohn's disease. Placebo response and remission rates for induction and maintenance trials were pooled by random-effects and mixed-effects meta-regression models to evaluate effects of study-level characteristics on these rates.

RESULTS

In 100 studies containing 67 induction and 40 maintenance phases and 7638 participants, pooled placebo remission and response rates for induction trials were 18% [95% confidence interval (CI) 16-21%] and 28% (95% CI 24-32%), respectively. Corresponding values for maintenance trials were 32% (95% CI 25-39%) and 26% (95% CI 19-35%), respectively. For remission, trials enrolling patients with more severe disease activity, longer disease duration and more study centres were associated with lower placebo rates, whereas more study visits and longer study duration was associated with higher placebo rates. For response, findings were opposite such that trials enrolling patients with less severe disease activity and longer study duration were associated with lower placebo rates. Placebo rates varied by drug class and route of administration, with the highest placebo response rates observed for biologics.

CONCLUSIONS

Placebo rates vary according to whether trials are designed for induction or maintenance and the factors influencing them differ for the endpoints of remission and response. These findings have important implications for clinical trial design in Crohn's disease.

Methotrexate for induction of remission in ulcerative colitis

BACKGROUND

Ulcerative colitis is a chronic inflammatory bowel disease. Corticosteroids and 5-aminosalicylates are the most commonly used therapies. However, many patients require immunosuppressive therapy when their disease becomes steroid-refractory or dependent. Methotrexate is a medication that is effective for treating a variety of inflammatory diseases, including Crohn's disease. This review was performed to determine the effectiveness of methotrexate at inducing remission in patients with ulcerative colitis.

OBJECTIVES

To review randomized trials examining the efficacy of methotrexate for remission induction in patients with ulcerative colitis.

SEARCH STRATEGY

MEDLINE (PUBMED), EMBASE, The Cochrane Central Register of Controlled Trials, the Cochrane IBD/FBD group specialized trials register, review papers on ulcerative colitis, and references from identified papers were searched in an effort to identify all randomized trials studying methotrexate use in patients with ulcerative colitis. Abstracts from major gastroenterological meetings were searched to identify research published in abstract form only.

SELECTION CRITERIA

Randomized controlled trials comparing methotrexate with placebo or an active comparator in patients with active ulcerative colitis were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by each author, analyzed on an intention-to-treat basis, and treated dichotomously. Methotrexate was compared to placebo in one trial. The odds ratio and 95% confidence interval were calculated and P-values were derived using the chi-square test.

MAIN RESULTS

Only 1 trial fulfilled the inclusion criteria. This study randomized 30 patients to methotrexate 12.5 mg orally weekly and 37 patients to placebo for 9 months. During the study period, 14/30 patients (47%) assigned to methotrexate, and 18/37 patients (49%) assigned to placebo achieved remission and complete withdrawal from steroids (OR 0.92, 95% CI 0.35-2.42; P = 0.87). The mean time to remission was 4.1 months in the methotrexate group and 3.4 months in the placebo group.

AUTHORS' CONCLUSIONS

A single trial of methotrexate 12.5 mg orally weekly showed no benefit over placebo in remission induction in patients with active ulcerative colitis. There is no evidence on which to base recommendations for treating ulcerative colitis patients with methotrexate. However, the possibility of a type 2 error exists, and a higher dose of methotrexate may be effective. A new trial in which adequate numbers of patients are randomized to placebo or a higher dose of methotrexate should be considered.

Natalizumab for induction of remission in Crohn's disease

BACKGROUND

The pathogenesis of Crohn's disease involves migration of leukocytes into gut tissue and subsequent inflammation. Natalizumab (Tysabri(R), Elan Pharmaceuticals and Biogen Idec) a recombinant humanized IgG4 monoclonal antibody that blocks adhesion and subsequent migration of leukocytes into the gut by binding the alpha4 integrin is a member of a new class of molecules known as selective adhesion molecule (SAM) inhibitors. The results of animal studies suggest that alpha4 integrin blockade could be a useful therapy for inflammatory bowel disease. The results of randomized controlled trials suggest that natalizumab may be an effective therapy for active Crohn's disease. This systematic review summarizes the current evidence on the use of natalizumab for the induction of remission in Crohn's disease.

OBJECTIVES

To determine the efficacy and safety of natalizumab for induction of remission in Crohn's disease.

SEARCH STRATEGY

A computer assisted search of the Cochrane Central Register of Controlled Trials, the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Review Group Specialized Trials Register, MEDLINE and EMBASE was performed to identify relevant publications between 1966 and September 2006. The medical subject heading (MeSH) terms "Crohn disease" or "inflammatory bowel disease", "Natalizumab" or "Antegren" or "Tysabri" and "Antibodies, Monoclonal" were used to perform key word searches of each database. Manual searches of reference lists from potentially relevant papers were performed in order to identify additional studies that may have been missed using the computer-assisted search strategy. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Personal contacts, leaders in the field, and the manufacturers were contacted to identify other studies which may not be published.

SELECTION CRITERIA

We included only randomized controlled trials comparing natalizumab to a placebo or control therapy for the induction of remission in Crohn's disease.

DATA COLLECTION AND ANALYSIS

Data were analyzed using Review Manager (RevMan 4.2.8). All data were analyzed on an intention-to-treat basis. For pooled data, summary test statistics were derived using the relative risk and 95% confidence intervals. Fixed and random effects models were used where appropriate. The definitions of treatment success, remission and clinical improvement were set by the authors of each paper, and the data were combined for analysis only if these definitions were sufficiently similar.

MAIN RESULTS

Pooled data from the four included studies suggest that natalizumab (300 mg or 3 to 4 mg/kg) is effective for induction of clinical response and remission in patients with moderately to severely active Crohn's disease. This benefit is statistically significant for one, two and three infusion treatments. There was a trend toward increased benefit with additional infusions of natalizumab. Natalizumab appears to provide greater benefit for patient subgroups characterized by objective confirmation of active inflammation or chronically active disease despite conventional therapies. These subgroup analyses demonstrated significantly greater clinical response and remission rates for natalizumab compared with placebo in patients with elevated C-reactive protein levels, active disease despite the use of immunosuppressants, or prior anti-tumor necrosis factor therapy. These benefits were apparent for both short term (one infusion) and longer term treatment (two or three infusions). Natalizumab was generally well tolerated and the safety profile observed in the four included studies was similar. Adverse events occurred infrequently and were experienced by a similar proportion of natalizumab and placebo treated patients. There were no statistically significant differences between natalizumab and placebo treated patients in the proportions of patients who withdrew due to adverse events or those who experienced serious adverse events. The included trials lacked adequate power to detect serious adverse events that occur infrequently. Recently, two patients with multiple sclerosis treated with natalizumab in combination with interferon beta-1a and one patient with Crohn's disease treated with natalizumab in combination with azathioprine developed progressive multifocal leukoencephalopathy (PML) resulting in two patient deaths. A retrospective investigation was conducted to assess the risk of PML in natalizumab treated patients and no new cases were identified.

AUTHORS' CONCLUSIONS

Pooled data suggest that natalizumab is effective for induction of clinical response and remission in some patients with moderately to severely active Crohn's disease. The clinical benefit of induction therapy with natalizumab in Crohn's disease should be weighed against the potential risk of serious adverse events. Preliminary data from the retrospective investigation of adverse events associated with natalizumab suggest that it may be possible to identify patients at risk for PML by testing for the appearance of JC virus in plasma.

Interventions for treating collagenous colitis

BACKGROUND

Collagenous colitis is a disorder that is recognized as a cause of chronic diarrhea. Treatment has been based mainly on anecdotal evidence. This review was performed to identify therapies for collagenous colitis that have been proven in randomized trials.

OBJECTIVES

To determine effective treatments for patients with clinically active collagenous colitis.

SEARCH STRATEGY

Relevant papers published between 1970 and June 2006 were identified via the MEDLINE and PUBMED databases. Manual searches from the references of identified papers, as well as review papers on collagenous or microscopic colitis were performed to identify additional studies. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Finally, the Cochrane Controlled Trials Register and the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register were searched for other studies.

SELECTION CRITERIA

Seven randomized trials were identified. One trial studied bismuth subsalicylate (published in abstract form only), one trial studied Boswellia serrata extract (published in abstract form only), one trial studied probiotics, one trial studied prednisolone, and 3 trials studied budesonide for the therapy of collagenous colitis.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by each author onto 2x2 tables (treatment versus placebo and response versus no response). For therapies assessed in one trial only, p-values were derived using the chi-square test. For therapies assessed in more than one trial, summary test statistics were derived using the Peto odds ratio and 95% confidence intervals. Data were combined for analysis only if the outcomes were sufficiently similar in definition.

MAIN RESULTS

There were 9 patients with collagenous colitis in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks). Those randomized to active drug were more likely to have clinical (p = 0.003) and histological (p = 0.003) improvement than those assigned to placebo. Eleven patients were enrolled in the trial studying prednisolone (50 mg daily for 2 weeks). There was a trend towards clinical response in patients on active medication compared to placebo (p = 0.064). The effect of prednisolone on histologic improvement was not studied. Thirty-one patients were enrolled in the Boswellia serrata extract trial. Clinical improvement was noted in 44% of patients who received active treatment compared to 27% of patients who received placebo (p = 0.32). Twenty-nine patients were enrolled in the probiotics trial. Clinical improvement was noted in 29% of patients who received probiotics compared to 13% of patients who received placebo (p = 0.635). A total of 94 patients were enrolled in 3 trials studying budesonide (9 mg daily or in a tapering schedule for 6 to 8 weeks). The pooled odds ratio for clinical response to treatment with budesonide was 12.32 (95% CI 5.53-27.46), with a number needed to treat of 2 patients. There was significant histological improvement with treatment in all 3 trials studying budesonide therapy. Budesonide also appears to improve patients' quality of life.

AUTHORS' CONCLUSIONS

Budesonide is effective for the treatment of collagenous colitis. The evidence for benefit with bismuth subsalicylate is weaker. The effectiveness of prednisolone, Boswellia serrata extract, probiotics and other therapies for induction or maintenance of remission of collagenous colitis is unknown and requires further study.

Interventions for treating collagenous colitis

BACKGROUND

Collagenous colitis is a disorder that is recognized as a cause of chronic diarrhea. Treatment has been based mainly on anecdotal evidence. This review was performed to identify therapies for collagenous colitis that have been proven in randomized trials.

OBJECTIVES

To determine effective treatments for patients with clinically active collagenous colitis.

SEARCH STRATEGY

Relevant papers published between 1970 and August 2003 were identified via the MEDLINE and PUBMED databases. Manual searches from the references of identified papers, as well as review papers on collagenous or microscopic colitis were performed to identify additional studies. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Finally, the Cochrane Controlled Trials Register and the Cochrane Inflammatory Bowel Disease Group Specialized Trials Register were searched for other studies.

SELECTION CRITERIA

Five randomized trials were identified. One trial studied bismuth subsalicylate (published in abstract form only), one trial studied prednisolone, and 3 trials studied budesonide in the therapy of collagenous colitis.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by each author onto 2x2 tables (treatment versus placebo and response versus no response). For therapies assessed in one trial only, p-values were derived using the chi-square test. For therapies assessed in more than one trial, summary test statistics were derived using the Peto odds ratio and 95% confidence intervals. Data were combined for analysis only if the outcomes were sufficiently similar in definition.

MAIN RESULTS

There were 9 patients with collagenous colitis in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks). Those randomized to active drug were more likely to have clinical (p=0.003) and histological (p=0.003) improvement than those assigned to placebo. Eleven patients were enrolled in the trial studying prednisolone (50 mg daily for 2 weeks). There was a trend towards clinical response in patients on active medication compared to placebo (p=0.064). The effect of prednisolone on histologic improvement was not studied. A total of 94 patients were enrolled in 3 trials studying budesonide (9 mg daily or in a tapering schedule for 6 to 8 weeks). The pooled odds ratio for clinical response to treatment with budesonide was 12.32 (95% CI 5.53-27.46), with a number needed to treat of 2 patients. There was significant histological improvement with treatment in all 3 trials studying budesonide therapy.

REVIEWER'S CONCLUSIONS

Budesonide is effective for the treatment of collagenous colitis. The evidence for benefit with bismuth subsalicylate is weaker. Prednisolone may be effective for treatment of collagenous colitis, but only a single very small study has been reported. The effectiveness of these and other therapies for induction or maintenance of remission (as opposed to producing clinical or histological improvement) of collagenous colitis is unknown.

Interventions for treating collagenous colitis

BACKGROUND

Collagenous colitis is a disorder that is recognized as a cause of chronic diarrhea. Treatment has been based mainly on anecdotal evidence. This review was performed to identify therapies for collagenous colitis that have been proven in randomized trials.

OBJECTIVES

To determine effective treatments for patients with clinically active collagenous colitis.

SEARCH STRATEGY

Relevant papers published between 1970 and October 2002 were identified via the MEDLINE, PUBMED, and EMBASE databases. Manual searches from the references of identified papers, as well as review papers on collagenous or microscopic colitis were performed to identify additional studies. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Finally, the Cochrane Controlled Trials Register and the Cochrane Inflammatory Bowel Disease Group Specialized Trials Register were searched for other studies.

SELECTION CRITERIA

Four randomized trials were identified. One trial studied bismuth subsalicylate (published in abstract form only), and 3 trials (1 published in abstract form only) studied budesonide in the therapy of collagenous colitis.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by each author onto 2x2 tables (treatment versus placebo and response versus no response). For therapies assessed in one trial only, p-values were derived using the chi-square test. For therapies assessed in more than one trial, summary test statistics were derived using the Peto odds ratio and 95% confidence intervals. Data were combined for analysis only if the outcomes were sufficiently similar in definition.

MAIN RESULTS

There were 9 patients with collagenous colitis in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks). Those randomized to active drug were more likely to have clinical (p=0.003) and histological (p=0.003) improvement than those assigned to placebo. A total of 94 patients were enrolled in 3 trials studying budesonide (9 mg daily for 6 to 8 weeks). The pooled odds ratio for clinical response to treatment with budesonide was 12.32 (95% CI 5.53-27.46), with a number needed to treat of 2 patients. There was significant histological improvement with treatment in all 3 trials studying budesonide therapy.

REVIEWER'S CONCLUSIONS

Budesonide is effective in the treatment of collagenous colitis. The evidence for bismuth subsalicylate is weaker, but still important. The roles of these and other therapies in inducing or maintaining remission (as opposed to clinical or histological improvement) of collagenous colitis are unknown.

Oral 5-aminosalicylic acid for induction of remission in ulcerative colitis

BACKGROUND

The newer 5-ASA preparations were intended to avoid the adverse effects of SASP while maintaining its therapeutic benefits. The efficacy and safety of 5-ASA preparations have been evaluated in numerous clinical trials that have often lacked sufficient statistical power to arrive at definitive conclusions. Previously, it was found that newer 5-ASA drugs in doses of at least 2g/day, were more effective than placebo but no more effective than SASP in inducing remission in ulcerative colitis. This updated review includes more recent studies and evaluates the effectiveness, dose-responsiveness, and safety of 5-ASA preparations in terms of more precise outcome measures.

OBJECTIVES

To assess the efficacy, dose-responsiveness and safety of the newer release formulations of 5-aminosalicylic acid (5-ASA) compared to placebo or sulfasalazine (SASP) for the induction of remission in active ulcerative colitis.

SEARCH STRATEGY

A computer-assisted literature search for relevant studies (1981-2003) was performed using MEDLINE, BIOS, the Cochrane Controlled Trials Register, the Cochrane IBD group specialized trials register and the Science Citation Index, followed by a manual search of reference lists from previously retrieved articles, review articles, symposia proceedings, and abstracts from major gastrointestinal conferences.

SELECTION CRITERIA

Studies were accepted for analysis if they were randomized, double-blinded, and controlled clinical trials of parallel design, with treatment durations of a minimum of four weeks.

DATA COLLECTION AND ANALYSIS

Based on an intention to treat principle, the outcomes of interest in the treatment of active disease were the failure to induce global/clinical remission, global/clinical improvement, endoscopic remission, or endoscopic improvement.

MAIN RESULTS

5-ASA was superior to placebo with regard to all measured outcome variables. For the failure to induce global/clinical improvement or remission, the pooled Peto odds ratio was 0.51 (95% CI, 0.35 to 0.76). A dose-response trend for 5-ASA was also observed. When 5-ASA was compared to SASP, the pooled Peto odds ratio was 0.87 (CI, 0.63 to 1.21) for the failure to induce global/clinical improvement or remission, and 0.66 (CI, 0.42 to 1.04) for the failure to induce endoscopic improvement. SASP was not as well tolerated as 5-ASA.

REVIEWER'S CONCLUSIONS

The newer 5-ASA preparations were superior to placebo and tended towards therapeutic benefit over SASP. However, considering their relative costs, a clinical advantage to using the newer 5-ASA preparations in place of SASP appears unlikely. This review updates the existing review of oral 5-aminosalicylic acid for induction of remission in ulcerative colitis which was published in the Cochrane Library (Issue 2, 2003).

Toward an accountability framework for Canadian healthcare

State-funded healthcare systems increasingly recognize accountability as an important public policy issue. This article explores significant aspects of current theory and practice in order to describe an accountability framework for the Canadian health system. Stakeholders include governments, institutions, providers and patients. Their relationships may be framed in constitutional, political, financial, managerial, clinical or ethical terms. The specific processes and instruments to operationalize accountability depend on the terms by which it is framed.

Accessory spleens in the thoracic and abdominal cavities after a relapse of idiopathic thrombocytopenic purpura: a case report

This case report presents a highly unusual finding of ectopic splenic tissue in both the thoracic and abdominal cavities in a patient with recurrent idiopathic thrombocytopenic purpura (ITP).

Sociodemographic and workload characteristics of dentists who participated in national survey, 1995

Comprehensive, standardized data on the sociodemographic characteristics and workload of dentists in different provinces and territories in Canada are not available. The authors mailed a survey to a stratified random sample of dentists (n = 6,444) with three follow-up attempts. The response rate was 66.4%. Significant provincial and territorial differences in sociodemographic characteristics included gender, age, years since graduation, marital status, population size of town or city where primary practice is located and patient load. There was considerable variation in dentists' workload: more than 10% of dentists from New Brunswick and Prince Edward Island reported seeing > or = 30 patients per day. The majority of respondents reported seeing patients for 25 to 40 hours per week. British Columbia, Ontario, Saskatchewan and Newfoundland had a greater proportion of respondents > or = 60 years of age compared with other provinces/territories, indicating that there may be more opportunities in these provinces for younger dentists as a result of retirements.

Compliance with recommended infection control procedures among Canadian dentists: results of a national survey

OBJECTIVES

The objective of this study was to investigate compliance with recommended infection control (IC) practices by dentists in Canada in 1995.

DESIGN

A mailed survey of a stratified random sample of dentists (N = 6444), with 3 follow-up attempts. Weighted analyses included multiple logistic regression to identify the best predictors of "excellent" compliance (18 items).

RESULTS

The adjusted response rate was 66.4%. Respondents reported use of an IC manual (52%); postexposure protocol (41%); biologic monitoring of heat-sterilizers (71%); hepatitis B immunization of dentists (91%: of these 72% had post-immunization screening; natural immunity 3%) all hygienists (78%), and all other clinical staff (70%); handwashing (before treating patients 76%, after degloving 63%); always wearing gloves (95%); changing gloves after each patient (97%); masks (82%); protective eyewear (82%); protective uniform (48%); puncture-proof container for sharps (94%); recapping needles with scoop technique/device (60%); flushing waterlines (55%); heat-sterilizing handpieces (94%; after each patient 77%); high-volume suction (92%) and "excellent" compliance (6%). Significant predictors of "excellent compliance" included attending continuing education about IC (>/=10 hours, odds ratio [OR] = 6.3; 6-10 hours, OR = 3.3), treating 20 to 29 patients per day (OR = 2.8), being women (OR = 2.7), and population of city in which practice is located (>500,000, OR = 2.5).

CONCLUSION

Improvements in IC are necessary in dental practice. The introduction of mandatory continuing education about IC may improve compliance with recommended IC procedures, which is important because of concerns related to transmission of bloodborne pathogens and drug-resistant microorganisms.

Infection control practices across Canada: do dentists follow the recommendations?

This study investigated provincial and territorial differences in dentists' compliance with recommended infection control practices in Canada (1995). Questionnaires were mailed to a stratified random sample of 6,444 dentists, of whom 66.4% responded. Weighted analyses included Pearson's chi-square test and multiple logistic regression. Significant provincial and territorial differences included testing for immune response after hepatitis B virus (HBV) vaccination, HBV vaccination for all clinical staff, use of infection control manuals and post-exposure protocols, biological monitoring of heat sterilizers, handwashing before treating patients, using gloves and changing them after each patient, heat-sterilizing handpieces between patients, and using masks and uniforms to protect against splatter of blood and saliva. Excellent compliance (compliance with a combination of 18 recommended infection control procedures) ranged from 0% to 10%; the best predictors were more hours of continuing education on infection control in the last two years, practice location in larger cities (> 500,000) and sex (female). Clearly, improvements in infection control are desirable for dentists in all provinces and territories. Extending mandatory continuing education initiatives to include infection control may promote better compliance with current recommendations.

Providers' perceptions of an immunization registry

OBJECTIVE

To determine providers' perceptions of a statewide immunization registry.

DESIGN

Mail survey.

SETTING

King County, Washington.

METHODS

A random sample of 700 pediatricians, family physicians, and RN/NPs were surveyed. In addition to their perceptions of registries, respondents reported their immunization procedures in the absence of immunization histories.

RESULTS

Of 544 eligible participants, 344 returned surveys (63% response rate). Seventy-seven percent of RN/NPs, 60% of pediatricians and 47% of family physicians (p < 0.001) responded that they thought that electronic immunization registries represented the "best chance to solve the lack of documentation problem." Fifty-seven percent of RN/NPs, 61% of pediatricians, and 43% of family physicians reported that the incompleteness of registry data presented a barrier to their using one (p < 0.01). Fewer than 14% of all specialties had concerns about potential compromises of patient confidentiality as a result of registries, although RN/NPs were more concerned about this possibility than both pediatricians and family physicians (p = 0.02). In a multivariate analysis, pediatricians were 43% less likely (p = 0.15) and family physicians were 73% less likely (p < 0.01) than RN/NPs to think registries are the solution to the lack of documentation problem. Familiarity with the existing registry was associated with a significant decrease in the likelihood of thinking that registries are the solution (OR .49 [.26-.90]) and an increase in the likelihood of thinking that registries will take a long time to become of practical value (OR 2.21 [1.09-4.29]).

CONCLUSIONS

Specialties differ with respect to their opinions regarding the promise immunization registries hold. Immunization registries appear to be well regarded in theory but may disappoint in practice. Incompleteness of immunization data may be the largest obstacle for registries to overcome.

The role of age- and population-based differences in the attitudes, knowledge and infection control practices of Canadian dentists

OBJECTIVES

To investigate age- and population-based differences in dentists' infection control practices and willingness and refusal to treat patients with HIV.

METHODS

A national mailed survey of a stratified random sample of dentists in Canada (n = 6444) with three follow-up attempts. Pearson's chi-square test and multiple logistic regression were used for data analysis. Predictor variables included population, age, gender, marital status, specialty, number of patients treated per day and continuing education on HIV/AIDS.

RESULTS

The adjusted response rate was 66.4%. The best predictors of willingness to treat patients with HIV were younger age (compared with dentists > or = 60 years of age: < 30 years, OR = 8.6, 30-39, OR = 3.4; 40-49, OR = 2.7; 50-59, OR = 1.6), attending continuing education on HIV/AIDS in the past 2 years (> 10 hours, OR = 1.6 compared with zero hours), practicing in small population centres < 10,000 (OR = 1.6 compared with > 500,000) and gender (male OR = 1.3). The best predictors of refusal to treat patients with HIV were older age (compared with dentists < 30 years of age: > or = 60, OR = 6.1; 50-59, OR = 4.1; 40-49, OR = 3.0; 30-39, OR = 2.6); and practicing in population centres > 500,000 (OR = 1.5 compared with < 10,000). However, the latter group also reported treating more HIV patients than respondents in smaller communities. Infection control practices varied significantly with age and population centre. Dentists in communities of < 10,000 were more compliant with HBV vaccination, but less compliant with handwashing after degloving and the use of infection control manuals. Similarly, dentists > 60 years of age were the least compliant with HBV immunization, routine use of barriers and sterilization of handpieces, but reported the highest compliance with handwashing.

CONCLUSIONS

Age- and population-based differences need to be considered in planning educational interventions to improve both access to care for patients with HIV and dentists' compliance with recommended infection control procedures.

Occupational injuries and exposures among Canadian dentists: the results of a national survey

OBJECTIVES

To measure the frequency of occupational exposures reported by dentists in Canada and to identify factors associated with occupational exposure.

DESIGN

A national mailed survey of a stratified random sample of 6,444 dentists with three follow-up attempts. Weighted data were analyzed using t tests, analysis of variance, and multiple logistic regression.

RESULTS

The response rate was approximately 66%. Occupational exposures, percutaneous injuries, and mucous membrane exposures in the last year were reported by 67%, 62%, and 29% of respondents, respectively. Fewer than 1% reported exposure to human immunodeficiency virus or hepatitis B virus (HBV). Respondents reported means of 1.5 mucous membrane and 3.0 percutaneous exposures per year. HBV immunization was reported by 91% of dentists, but of these 28% reported no post-immunization serology. Other reports of suboptimal compliance included use of a postexposure protocol by only 41% and HBV vaccination of all assistants or of hygienists by 74% and 77% of respondents, respectively. Factors associated with percutaneous exposure included non-use of postexposure protocol or puncture-proof containers for sharps disposal, treating > or =20 patients per day, and male gender. Risk factors for mucous membrane exposure included non-use of eye protection or masks.

CONCLUSION

This study provides evidence of the protective effect of puncture-proof containers, eye protection, and masks and raises concerns related to HBV post-immunization serology and postexposure protocols. To reduce risk of infection, educational interventions are required to improve compliance with Universal Precautions, with emphasis on comprehensive HBV immunization and post-immunization serology, the use of barriers, puncture-proof containers for sharps disposal, and postexposure protocols.

Factors associated with refusal to treat HIV-infected patients: the results of a national survey of dentists in Canada

OBJECTIVES

This study investigated dentists refusal to treat patients who have HIV.

METHODS

A survey was mailed to a random sample of all licensed dentists in Canada, with 3 follow-up attempts (n = 6444). Data were weighted to allow for probability of selection and nonresponse and analyzed with Pearson's chi 2 and multiple logistic regression.

RESULTS

The response rate was 66%. Of the respondents, 32% had knowingly treated HIV-infected patients in the last year; 16% would refuse to treat HIV-infected patients. Respondents reported willingness to treat HIV-infected patients (81%), injection drug users (86%), hepatitis B virus-infected patients (87%), homosexual and bisexual persons (94%), individuals with sexually transmitted disease(s) (94%), and recipients of blood and blood products (97%). The best predictors of refusal to treat patients with HIV were lack of ethical responsibility (odds ratio = 9.0) and items related to fear of cross-infection or lack of knowledge of HIV.

CONCLUSIONS

One in 6 dentists reported refusal to treat HIV-infected patients, which was associated primarily with respondents' lack of belief in an ethical responsibility to treat patients with HIV and fears related to cross-infection. These results have implications for undergraduate, postgraduate, and continuing education.

Improved compliance with recommended infection control practices in the dental office between 1994 and 1995

OBJECTIVE

To investigate changes in Ontario dentists' infection control practices between 1994 and 1995.

METHODS

Data from responses of 4003 dentists to a 1994 survey and responses of 987 dentists to a 1995 survey were compared by using descriptive statistics from all respondents and McNemar's test for paired data from those participating in both surveys.

RESULTS

Response rates were 70% (1994) and 62% (1995). There were improvements in reports of routine use of gloves (92% to 94%); masks (73% to 79%); and protective eyewear (83% to 84%); vaccination for hepatitis B virus (HBV) or naturally acquired immunity of dentists (93% to 94%); HBV vaccination of clinical staff (64% to 77%); heat sterilization of handpieces (83% to 95%); and no extra precautions for patients with HIV (13% to 48%). Pairwise comparison of data for 788 dentists participating in both surveys showed statistically significant increases in reports of all practices except use of protective eyewear. The 1995 follow-up data also indicated low compliance with handwashing (74% before treating each patient; 62% after removing gloves); flushing water lines after treating each patient (54%); and using postexposure protocol for needlesticks and cuts (36%).

CONCLUSIONS

Dentists' reports of compliance with recommended infection control practices and universal precautions against HBV and HIV infection increased between 1994 and 1995, but most dentists apparently have not adopted universal precautions. More education is needed to promote universal precautions, HBV vaccination for clinical staff, handwashing, and postexposure protocol.

A comparison of infection control practices of different groups of oral specialists and general dental practitioners

OBJECTIVE

The purpose of this study was to compare the infection control practices of general dentists and dental specialty groups.

METHODS

A survey was mailed to 5997 dentists in 1994; the response rate was 70%. The data were analyzed with multiple logistic regression (reference group: general dentists).

RESULTS

When sociodemographic influences were taken into consideration, significant predictors of routine infection control practices included all of the following characteristics (odds ratios are in parentheses): 1. Gloves: being younger than 40 years of age (4.5) and being female (5.9). 2. Using gloves and changing gloves after each patient: being younger than 40 years of age (4.0), being female (3.0), being an oral surgeon (3.6), and being an orthodontist (0.2). 3. Using gloves, masks, and protective eyewear: being younger than 40 years of age (2.5), being female (2.3), and being an orthodontist, oral physician, or oral pathologist (0.2). 4. Hepatitis B vaccination for the practitioner: being younger than 40 years of age (5.1). 5. Hepatitis B vaccination for all clinical staff members: being younger than 40 years of age (1.2), being an oral surgeon (1.7), and being an orthodontist (0.6). 6. Heat sterilization of handpieces: being younger than 40 years of age (1.5), being an oral surgeon (5.4), and being an orthodontist (0.2). 7. Taking no additional precautions for patients with HIV: being younger than 40 years of age (1.7), being a periodontist (2.6), being a pedodontist (2.3), and being an oral physician/oral pathologist (4.3).

CONCLUSION

Improved compliance with recommended infection control procedures is required for all groups and is particularly necessary for orthodontists.

Active and passive surveillance for communicable diseases in child care facilities, Seattle-King County, Washington

OBJECTIVES

The purpose of this study was to develop and evaluate models for public health surveillance of illnesses among children in out-of-home child care facilities.

METHODS

Between July 1992 and March 1994, 200 Seattle-King County child care facilities participated in active or enhanced passive surveillance, or both. Reporting was based on easily recognized signs, symptoms, and sentinel events. Published criteria were used in evaluating surveillance effectiveness, and notifiable disease reporting of participating and nonparticipating facilities was compared.

RESULTS

Neither surveillance model was well accepted by child care providers. Enhanced passive and active surveillance had comparable sensitivity. Reporting delays and the large amount of time needed for data entry led to problems with timeliness, especially in terms of written reporting during active surveillance.

CONCLUSIONS

Widespread active public health surveillance in child care facilities is not feasible for most local health departments. Improvements in public health surveillance in child care settings will depend on acceptability to providers.

Illnesses and absence due to illness among children attending child care facilities in Seattle-King County, Washington

OBJECTIVES

Although much of the economic impact of child care-associated illness in the United States is due to parents' time lost from work, there are no data on the incidence of absence due to illness among children in various types of out-of-home child care settings in the United States. The goals of this study were to compare the incidence of illness and absence due to illness among children attending child care homes (CCHs) and child care centers (CCCs).

METHODS

From July 1992 through June 1993, child care providers from 91 CCHs and 41 CCCs in Seattle-King County, Washington, provided information on absenteeism and illness for 96 792 child-weeks of observation.

RESULTS

The age-adjusted incidence of provider-reported illness episodes among children in CCHs (10.4 episodes per 100 child-weeks) was greater than that among children in CCCs (6.7 episodes per 100 child-weeks). The incidence density ratio of illness among children <1 year of age in comparison to those >/=5 years of age in CCCs (4.5) was greater than that among similar groups in CCHs (2.3). The age-adjusted incidence of absence due to illness among children in CCHs (5.1 days per 100 child-weeks) was less than that among children in CCCs (8.9 days per 100 child-weeks).

CONCLUSIONS

Results comparing the incidence of illness between children in various types of child care settings may be influenced by information sources. The incidence of illness among children in CCHs may be greater than that among children in CCCs. The increased incidence of absence due to illness among children in CCCs compared with that among children in CCHs probably reflects differences in exclusion and attendance policies and practices between these two types of settings.

The infection control practices of general dental practitioners

OBJECTIVES

To investigate the infection control practices of general dentists in Ontario in 1994.

DESIGN

Confidential coded questionnaires were mailed to all general dental practitioners in Ontario (n = 5,176), with three follow-up attempts. Data were analyzed using Pearson's chi-squared test and multiple logistic regression.

SETTING

Offices of general dental practitioners in Ontario.

PARTICIPANTS

General dental practitioners actively involved in treating patients.

RESULTS

The response rate adjusted for nondelivery was 70%. A high proportion of respondents reported using gloves (always, 91.8%; sometimes, 7.8%), masks (always, 74.8%; sometimes, 21.1%), or protective eyewear (always, 83.6%; sometimes, 13%); heat sterilization of handpieces (83.9%); and hepatitis B (HBV) vaccination of dentists (92.3%). However, only 61.4% of respondents reported HBV vaccination of all clinical staff, and 87.7% used additional precautions for patients with human immunodeficiency virus (HIV). Significant predictors of the use of recommended infection control procedures (i.e., always using gloves, masks, and eye protection; heat sterilization of handpieces; HBV vaccination for dentist and staff; and no extra precautions for patients with HIV) were age < 40 years (odds ratio [OR], 2.6), lack of concern regarding increased personal risk (OR, 2.0) or costs of infection control procedures (OR, 1.5), and knowledge of the low infectivity of HIV after a needlestick injury (OR, 2.0) and that infection control procedures for HBV are adequate for HIV (OR, 2.7).

CONCLUSION

Additional education is required to promote a more realistic perception of risk of HIV transmission in the dental office and the use of all recommended infection control practices, including Universal Precautions.

Infection control in the orthodontic office in Canada

Because of the difficulty of identifying infected persons, current recommendations for infection control are to treat all patients as if they are infected with blood-borne pathogens such as human immunodeficiency virus (HIV) and the hepatitis viruses. Dentists' compliance with these recommendations has been investigated previously, however, there are few data related to orthodontists. The objective of this study was to measure the proportion of orthodontists who report the use of recommended infection control procedures and to compare the infection control practices of orthodontists and general dentists. A mailed survey with three follow-up attempts was administered to all orthodontists and general dentists in Ontario (N = 5441) in 1994. There were significant differences in the routine use of gloves (orthodontists 85%, general dentists 92%); masks (orthodontists 38%, general dentists 75%); protective eyewear (orthodontists 60%, general dentists 84%); changing gloves after each patient (orthodontists 84%, general dentists 96%); and heat sterilization of handpieces (orthodontists 57%, general dentists 84%). Hepatitis B virus (HBV) vaccination of all clinical staff was reported by 46% of orthodontists, compared with 61% of general dentists (p < 0.001). Reports of HBV vaccination of orthodontists (94%) and general dentists (92%) were not significantly different. The use of additional precautions for patients with HIV was reported by 80% of orthodontists and 78% of general dentists. More education is required to promote the use of universal precautions by both general practitioners and orthodontists. Increased use of barrier methods, HBV vaccination of clinical staff, and heat sterilization of handpieces is required to reduce the potential for cross infection in the orthodontic practice. This is particularly important with the increasing number of microorganisms that are resistant to antibiotics.

Nonresponse bias in a national study of dentists' infection control practices and attitudes related to HIV

The aim was to investigate late response and nonresponse bias in a survey related to HIV and infection control. Questionnaires with ID numbers were mailed to a stratified random sample of dentists in Canada with additional mailings 4 and 7 weeks later (n = 6444). We compared responses received after < 4 weeks, 4-7 weeks, > 7 weeks. Extrapolation was used to estimate nonresponse bias. Univariate analyses showed significant differences between responses received < 4 weeks after initial mailing and those received later for items on sociodemographics, knowledge, infection control practices and attitudes: late responders were more likely to report that they would refuse to treat any patients with HIV (P < 0.01). Multiple logistic regression indicated that the best predictors of responses received > or = 4 weeks were disagreement that HBV is more infectious than HIV (OR = 1.7); unwillingness to attend a dentist who treats HIV/AIDS patients (OR = 1.3); incorrect perception of the risk of HIV infection after an HIV-contaminated needlestick injury (OR = 1.2); and sometimes or never heat-sterilizing handpieces after each patient (OR = 1.2). Extrapolation indicated that the percentage of all respondents who reported refusal to treat (15.2%) would have been 17.1% if a 100% response rate had been obtained. We found significant evidence of late response and nonresponse bias primarily in knowledge and fears related to HIV infectivity; however, the impact on the final results was small and we concluded that additional follow-up to improve response rates would not be worthwhile.

Nonresponse bias in a survey of Ontario dentists' infection control and attitudes concerning HIV

OBJECTIVE

This study investigated late response and nonresponse bias in an HIV-related survey of dentists.

METHODS

Questionnaires with ID numbers were mailed to all dentists in Ontario (N = 5,997) with additional mailings four and seven weeks later.

RESULTS

Proportionately more respondents who returned questionnaires less than four weeks after the first mailing reported that they knowingly treated (P < .05) or were willing to treat HIV-infected patients (P < .05); that they had an accurate perception of risk of HIV infection after a needlestick injury (P < .01), and preferred not to refer HIV-infected patients (P < .01). Linear extrapolation of cumulative percent responses indicated nonresponse bias in terms of attitude and knowledge items; however, the magnitude was low.

CONCLUSIONS

The effects of late response and nonresponse bias on the results of this study were small. However, these results cannot be generalized beyond the study population, and obtaining high response rates and testing for nonresponse bias in surveys of attitudes related to HIV are recommended.

Gender differences in characteristics, infection control practices, knowledge and attitudes related to HIV among Ontario dentists

We surveyed 5,997 dentists in Ontario to investigate gender differences in the characteristics, infection control practices, knowledge and attitudes regarding the treatment of HIV-infected patients. The response rate was 70.3%. Reports indicated that female dentists are younger and more likely to work in larger urban centres (P < 0.00001), and in general practice (P < 0.0001) than their male counterparts. Multiple logistic regression analyses indicated that many significant gender differences in the univariate analyses could be explained by the confounding influence of age, practice location, and specialty; however, some differences remain significant: Women were more likely than men to report attending continuing education dealing with HIV/AIDS in the past two years (P < 0.001), and to use masks and eye protection (P < 0.00001). Men reported more economic concerns than women: they were more concerned about the financial burden of infection control costs (P < 0.00001), and losing patients from their practice if it is known that they treat patients with HIV (P < 0.05). However, there were no significant differences in willingness to provide treatment for patients with HIV. We conclude that there is little evidence to show that access to oral care for patients with HIV is affected by gender differences.

Quitting smoking: why, how, and what might help

OBJECTIVE

To examine reasons for quitting smoking, methods used in quitting, reasons for continuing smoking and potential aids to quitting in the population of Ontario, Canada.

DESIGN

Two population-based, telephone interview surveys, conducted by random-digit dialing.

SUBJECTS

Adults aged 18 years of age and older in 1983 (n = 1383) and 1991 (n = 1421).

MAIN OUTCOME MEASURES

Information was obtained from former smokers on why and how they quit smoking, and from continuing smokers on why they smoked and what might help them quit.

RESULTS

The proportion of current smokers in the population decreased from 35.5% in 1983 to 27.2% in 1991. In both surveys, former smokers cited a variety of reasons for quitting, including personal health concerns, social and environmental factors, personal attitude factors, cost, and health education messages. Responses concerning the most important reason also revealed a range of factors; "advice of a physician" was not prominent among them. When questioned about methods used in quitting, most former smokers in both surveys responded that they "just decided to quit". Very few reported using other aids such as cessation clinics or nicotine gum. More smokers in 1991 than in 1983 reported that they continued smoking for enjoyment, to satisfy a craving or addiction, and for relaxation. With regard to what might help them quit, continuing smokers in both surveys cited a wide variety of potential aids, including information on harmful effects, more restrictions on smoking and on sales, cessation clinics, programmes on radio/TV, and higher taxes.

CONCLUSIONS

These findings support a multifaceted approach to tobacco control.

Injuries and their relation to potential hazards in child day care

OBJECTIVES

To prospectively determine the incidence rate of injuries that required medical attention among children in day care and to identify possible hazards related to these injuries.

SETTING

King County, Washington.

METHODS

Prospective cohort study of children in a sample of licensed day care facilities.

RESULTS

From 1 July 1992 to 30 June 1993, 53 medically attended injuries were reported by 133 day care sites; incidence rate 1.9 per 100,000 hours of day care attendance. The rate of injury in 91 small family day care homes was essentially the same as that in 42 larger day care centers; relative rate 1.0 (95% confidence interval 0.6 to 1.9). Injuries that required sutures accounted for 39% of the cases, while 17% required a cast, splint, or sling. No child was hospitalized. Sixty nine sites were inspected and all had potentially correctable physical hazards, with a median of 15 hazards per site (range 7 to 26). These potential hazards had little relationship to the risk of injury and a case-by-case review identified only two injuries that might have been prevented by a more energy absorbent playground surface.

CONCLUSIONS

The incidence of medically attended injuries found in this study is consistent with other studies from the United States. Most injuries were minor and had little relation to physical hazards at day care locations.

Geographic differences in the attitudes, knowledge and infection control practices of Ontario dentists

Geographic differences in the HIV related attitudes, knowledge and behaviours of 5,997 dentists in Ontario were investigated using mailed questionnaires (response rate 70%). Proportionately more respondents from larger population centres reported that they knowingly treated HIV-infected patients (p < 0.00001), they were unwilling to treat HIV-infected patients (p < 0.05), they had an exaggerated perception of the risk of HIV infection after a needlestick injury (p < 0.01), they were concerned about personal risk (p < 0.01) and staff fears (p < 0.05) related to HIV/AIDS, and that patients with HIV or AIDS should be treated in hospitals/specialized practices (p < 0.001). Multiple logistic regression analysis controlling for age, sex, and specialty, showed that respondents who practised in smaller population centres were significantly more willing to treat HIV-infected patients ( < 10,000, odds ratio = 1.6; 10,000-49,999, odds ratio = 1.3). Significantly fewer respondents in the Central West, and Central East Health Planning Region, where AIDS is most prevalent, reported that they were willing to treat HIV patients.

Syrinx extending from conus medullaris to basal ganglia: a clinical, radiological, and pathological correlation

A 41-year-old woman with a history of birth injury to the brachial plexus suffered several delayed episodes of neurological deterioration. Magnetic resonance imaging studies revealed a syrinx extending from the conus medullaris into the brainstem and rostrally into both internal capsules. She died of an acute exacerbation of chronic respiratory failure. Autopsy demonstrated syringomyelia and syringobulbia with cavity extension bilaterally along the corticospinal tracts into the internal capsules. Islands of glial tissue in the subarachnoid space around the medulla caused obstruction of the subarachnoid space at the foramen magnum. These were probably the result of birth injury to the cerebellum. A detailed clinico-pathological correlation is provided to explain her neurological deficits. The pathogenesis of syrinx formation is discussed in terms of a late manifestation of birth trauma.