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Context: Poor patient-physician communication increases the risk of patient complaints and malpractice claims. To address this problem, licensure assessment has been reformed in Canada and the United States, including a national standardized assessment of patient-physician communication and clinical history taking and examination skills., Objective: To assess whether patient-physician communication examination scores in the clinical skills examination predicted future complaints in medical practice., Design, Setting, and Participants: Cohort study of all 3424 physicians taking the Medical Council of Canada clinical skills examination between 1993 and 1996 who were licensed to practice in Ontario and/or Quebec. Participants were followed up until 2005, including the first 2 to 12 years of practice., Main Outcome Measure: Patient complaints against study physicians that were filed with medical regulatory authorities in Ontario or Quebec and retained after investigation. Multivariate Poisson regression was used to estimate the relationship between complaint rate and scores on the clinical skills examination and traditional written examination. Scores are based on a standardized mean (SD) of 500 (100)., Results: Overall, 1116 complaints were filed for 3424 physicians, and 696 complaints were retained after investigation. Of the physicians, 17.1% had at least 1 retained complaint, of which 81.9% were for communication or quality-of-care problems. Patient-physician communication scores for study physicians ranged from 31 to 723 (mean [SD], 510.9 [91.1]). A 2-SD decrease in communication score was associated with 1.17 more retained complaints per 100 physicians per year (relative risk [RR], 1.38; 95% confidence interval [CI], 1.18-1.61) and 1.20 more communication complaints per 100 practice-years (RR, 1.43; 95% CI, 1.15-1.77). After adjusting for the predictive ability of the clinical decision-making score in the traditional written examination, the patient-physician communication score in the clinical skills examination remained significantly predictive of retained complaints (likelihood ratio test, P < .001), with scores in the bottom quartile explaining an additional 9.2% (95% CI, 4.7%-13.1%) of complaints., Conclusion: Scores achieved in patient-physician communication and clinical decision making on a national licensing examination predicted complaints to medical regulatory authorities.

Purpose: Although bronchial artery embolization (BAE) is effective in the acute control of recurrent or major hemoptysis in adults with cystic fibrosis, outcomes after embolization are not well known. The objective of this retrospective study was to evaluate respiratory function, survival, and hemoptysis-free survival in adult patients with cystic fibrosis treated for hemoptysis with BAE., Materials and Methods: Of 297 patients with cystic fibrosis hospitalized from 1990 to 2004, 30 patients (mean age, 26.7+/-9.2 years) presented with major or persistent hemoptysis that required 42 BAE sessions. These patients were compared with a control group of 27 patients without hemoptysis requiring embolization who were matched for age, sex, and forced expiratory volume in 1 second (FEV1)., Results: Hemoptysis stopped within 24 hours after BAE in 96.6% of patients (n=29), and there were no major complications. The change in the slope of FEV1 after the BAE or matching date was significantly worse in the embolization group (P=.0007). At last follow-up, nine and one patients, respectively, had undergone lung transplantation in the BAE and control groups (P=.002). The 5-year survival rates without lung transplantation were 31% and 84%, respectively, in the BAE and control groups (hazard ratio, 5.95; P=.002). Sixty-two percent of patients were free of hemoptysis 5 years after BAE. The number of collateral arteries was the only factor associated with the risk of death or recurrent hemoptysis (P=.001)., Conclusions: Despite the effectiveness of embolization in controlling recurrent or major hemoptysis, adults with cystic fibrosis who have undergone BAE for hemoptysis are at much higher risk of respiratory function aggravation, death, and the need for lung transplantation than those who have not undergone BAE for hemoptysis. They are more likely to die or to undergo lung transplantation than to present with recurrent major hemoptysis.

Background and Objectives: Accurate assessment of medication impact requires modeling cumulative effects of exposure duration and dose; however, postmarketing studies usually represent medication exposure by baseline or current use only. We propose new methods for modeling various aspects of medication use history and employment of them to assess the adverse effects of selected benzodiazepines., Study Design and Setting: Time-dependent measures of cumulative dose or duration of use, with weighting of past exposures by recency, were proposed. These measures were then included in alternative versions of the multivariable Cox model to analyze the risk of fall related injuries among the elderly new users of three benzodiazepines (nitrazepam, temazepam, and flurazepam) in Quebec. Akaike's information criterion (AIC) was used to select the most predictive model for a given benzodiazepine., Results: The best-fitting model included a combination of cumulative duration and current dose for temazepam, and cumulative dose for flurazepam and nitrazepam, with different weighting functions. The window of clinically relevant exposure was shorter for flurazepam than for the two other products., Conclusion: Careful modeling of the medication exposure history may enhance our understanding of the mechanisms underlying their adverse effects.

Objective: Treatment recommendations for fibromyalgia (FM) include regular physical exercise. In this prospective study we examined predictors for adherence to stretching and aerobic exercises in women provided with an individualized home based program., Methods: Thirty-nine women kept exercise diaries for 12 weeks., Results: For both types of exercise, women who were less physically fit at baseline engaged in more exercise during the program. Yet for stretching, more lower body pain at baseline predicted engaging in less stretching exercise over time, whereas for aerobic exercise, more baseline upper body pain predicted more exercise over time. As time passed, participants with higher baseline physical fitness and/or older age were reducing their aerobic exercise practice at significantly faster rates, as were those women with higher baseline stress., Conclusion: Given that adequate levels of adherence were limited to about half of the participants for both types of exercise, steps to reduce barriers to exercise (e.g., stress) need to be taken when prescribing exercise in the treatment of FM.

Background: Previous findings regarding risk factors for human papillomavirus (HPV) persistence, other than viral determinants, identified from prospective cohort studies have been inconsistent in part because study designs have differed with respect to differing HPV detection methods and varying lengths of follow-up time. Therefore, the objectives of this study were to continue the search for epidemiologic risk factors of persistent cervical HPV infections and determine what behaviors differed between those women with transient HPV infections and those women who cannot clear their type-specific HPV infections., Methods: Female university students (n = 621) in Montreal were followed for 24 months at 6-month intervals. At each visit, a cervical cell specimen was collected. HPV DNA was detected using the MY09/MY11 PCR protocol and 27 HPV genotypes were identified by the line blot assay (Roche Molecular Systems, Inc., Alameda, CA). Proportional hazards regression was used to estimate the crude and adjusted hazard ratios of clearing a type-specific high-risk (n = 222) or low-risk (n = 105) HPV infection over time according to specific baseline and time-dependent covariates., Results: Daily consumption of vegetables seemed to increase the rate of HPV clearance independent of type. The use of tampons was associated with a reduced rate of high-risk HPV clearance, whereas regular condom use was associated with an increased rate of low-risk HPV clearance only., Conclusion: Some proactive measures can be taken to increase the rate of HPV clearance, and there may be some differences between the sets of predictors of low-risk and high-risk HPV clearance.

Objectives: To determine the risk of injury associated with the new use of individual benzodiazepines and dosage regimens in the elderly., Design: Prospective database cohort study with 5 years of follow-up., Setting: Quebec, Canada., Participants: Two hundred fifty-three thousand two hundred forty-four persons aged 65 and older who were nonusers of benzodiazepines in the year before follow-up., Measurements: Population-based hospitalization and prescription and medical services claims databases were used to compare the risk of injury during periods of benzodiazepine use with those of nonuse. Periods of use were measured for 10 insured benzodiazepines by drug and dose as time-dependent covariates. Injury was defined as the first occurrence of a nonvertebral fracture, soft-tissue injury, or accident-related hospital admission. Patient age, sex, previous injury history, concomitant medication use, and comorbidity were measured as fixed and time-dependent confounders. Cox proportional hazards models were used to estimate the risk of injury with benzodiazepine use and to determine the extent to which patient characteristics, differences in dosage, or in the effect of increasing dosage for individual drugs explained differences between drugs., Results: More than one-quarter (27.6%) of 253,244 elderly were dispensed at least one prescription for a benzodiazepine, and 17.7% of elderly were treated for at least one injury during follow-up, of which fractures were the most common. Patient characteristics, systematic differences in the risk of injury in elderly prescribed different benzodiazepines, and differences in dosage prescribed for individual drugs confounded the risk of injury with benzodiazepine use. The risk of injury with increasing dosage varied by drug from a hazard ratio of 0.92 (95% confidence interval (CI)=0.60, 1.42) for alprazolam to 2.20 (95% CI=1.39, 3.47) for flurazepam per 1 standardized adult dose increase., Conclusion: The risk of injury varied by benzodiazepine, independent of half-life, as did the risk associated with increasing dosage for individual products. Higher doses of oxazepam, flurazepam, and chlordiazepoxide are associated with the greatest risk of injury in the elderly.

The impact of covariate aggregation, well studied in relation to linear regression, is less clear in the Cox model. In this paper, the authors use real-life epidemiologic data to illustrate how aggregating individual covariate values may lead to important underestimation of the exposure effect. The issue is then systematically assessed through simulations, with six alternative covariate representations. It is shown that aggregation of important predictors results in a systematic bias toward the null in the Cox model estimate of the exposure effect, even if exposure and predictors are not correlated. The underestimation bias increases with increasing strength of the covariate effect and decreasing censoring and, for a strong predictor and moderate censoring, may exceed 20%, with less than 80% coverage of the 95% confidence interval. However, covariate aggregation always induces smaller bias than covariate omission does, even if the two phenomena are shown to be related. The impact of covariate aggregation, but not omission, is independent of the covariate-exposure correlation. Simulations involving time-dependent aggregates demonstrate that bias results from failure of the baseline covariate mean to account for nonrandom changes over time in the risk sets and suggest a simple approach that may reduce the bias if individual data are available but have to be aggregated.

Purpose: To characterize longitudinal patterns of Benzodiazepine use in the elderly., Methods: Prospective cohort of 78 367 community-dwelling Quebec residents aged 66 years or more who were new Benzodiazepine users, was followed for 5 years, 1989-1994. Data acquired from four population-based, provincial administrative databases were used to create time-dependent measures of change in dosage, switching or adding Benzodiazepines for 11 drugs listed in the provincial formulary. Subject-specific Spearman's rank correlation coefficients between dose and time were used to measure the tendency of increasing dose with consecutive periods of use. Multiple logistic regression and generalized estimating equations (GEE) models evaluated subject characteristics associated with increasing dose., Results: The mean duration of uninterrupted Benzodiazepine use was 75.5 days. The mean daily dose was about half the recommended adult daily dose but 8.6% of subjects exceeded the recommended adult dose. Some of them (28.8%) switched medications at least once and 8.2% filled two or more prescriptions concurrently. For women, older age at date of first prescription was associated with increasing dose over time (odds ratio (OR) for 10 year age increase = 1.23, p < 0.001)., Conclusion: Long periods of Benzodiazepine use are frequent among Quebec elderly. The evidence of increasing dose, particularly for older women, and long-duration of use has important implications for clinicians., (2003 John Wiley & Sons, Ltd.)

Accurate estimation of the exposure-response relationship between environmental particulate air pollution and mortality is important from both an etiologic and regulatory perspective. However, little is known about the actual shapes of these exposure-response curves. The objective of this study was to estimate the exposure-response relationships between mortality and long-term average city-specific levels of sulfates and fine particulate matter (PM(2.5)). We reanalyzed the data derived from the American Cancer Society (ACS) Cancer Prevention Study II, a large prospective study conducted in the United States between 1982 and 1989. Exposure to particulate air pollution was assessed prior to entry into the cohort. Mean sulfate concentrations for 1980 were available in 151 cities, and median PM(2.5) levels between 1979 and 1983 were available in 50 cities. Two sampling strategies were employed to reduce the computational burden. The modified case-cohort approach combined a random subcohort of 1200 individuals with an additional 1300 cases (i.e., deaths). The second strategy involved pooling the results of separate analyses of 10 disjoint random subsets, each with about 2200 participants. To assess the independent effect of the particulate levels on all-causes mortality, we relied on flexible, nonparametric survival analytical methods. To eliminate potentially restrictive assumptions underlying the conventional models, we employed a flexible regression spline generalization of the Cox proportional-hazards (PH) model. The regression spline method allowed us to model simultaneously the time-dependent changes in the effect of particulate matter on the hazard and a possibly nonlinear exposure-response relationship. The PH and linearity hypotheses were tested using likelihood ratio tests. In all analyses, we stratified by age and 5-yr age groups and adjusted for the subject's age, lifetime smoking exposure, obesity, and education. For both fine particles (PM(2.5)) and sulfates, there was a statistically significant (at.05 level) departure from the conventional linearity assumption. The adjusted effect of fine particles on mortality indicated a stronger relationship in the lower (up to about 16 microg/m(3)) than in the higher range of their values. Increasing levels of sulfates in the lower range (up to about 12 microg/m(3)) had little impact on mortality, suggesting a possible "no-effect threshold." For body mass index (BMI), the risks were lowest in the middle range and increased for both very obese and very lean individuals. It was concluded that flexible modeling yields new insights about the effect of long-term air pollution on mortality.

Objective: The frequency of coronary heart disease (CHD) and stroke are increased in systemic lupus erythematosus (SLE), but the extent of the increase is uncertain. We sought to determine to what extent the increase could not be explained by common risk factors., Methods: The participants at two SLE registries were assessed retrospectively for the baseline level of the Framingham study risk factors and for the presence of vascular outcomes: nonfatal myocardial infarction (MI), death due to CHD, overall CHD (nonfatal MI, death due to CHD, angina pectoris, and congestive heart failure due to CHD), and stroke. For each patient, the probability of the given outcome was estimated based on the individual's risk profile and the Framingham multiple logistic regression model, corrected for observed followup. Ninety-five percent confidence intervals (95% CIs) were estimated by bootstrap techniques., Results: Of 296 SLE patients, 33 with a vascular event prior to baseline were excluded. Of the 263 remaining patients, 34 had CHD events (17 nonfatal MIs, 12 CHD deaths) and 16 had strokes over a mean followup period of 8.6 years. After controlling for common risk factors at baseline, the increase in relative risk for these outcomes was 10.1 for nonfatal MI (95% CI 5.8-15.6), 17.0 for death due to CHD (95% CI 8.1-29.7), 7.5 for overall CHD (95% CI 5.1-10.4), and 7.9 for stroke (95% CI 4.0-13.6)., Conclusion: There is a substantial and statistically significant increase in CHD and stroke in SLE that cannot be fully explained by traditional Framingham risk factors alone.

Objective: New scales for the clinical assessment of patients with systemic lupus erythematosus (SLE) are valid and reliable, and quantitate disease activity. We assessed the responsiveness to change of 2 widely used standardized multi-item lupus activity measures, the revised Systemic Lupus Activity Measure (SLAM-R) and the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and their ability to detect clinically relevant changes., Methods: Ninety-six (96) patients with definite SLE participated in this study. The group mean age was 45.0 (13.7) years, 91% were female, and the mean disease duration was 14.9 (7.5) years. Sociodemographic information, lupus activity (SLAM-R, SLEDAI), and damage were recorded at baseline. At each of the 5 monthly followup visits, the activity measures were repeated and a transition scale asked the physician if their patient's lupus activity had changed. Five different methods were used to compare the responsiveness of the activity measures studied: 1. the effect size; 2. the standardized response mean; 3. the control standardized response mean; 4. the area under the curve of a receiver operating characteristic (ROC) curve; and 5. a new multiple response modeling approach., Results: Both SLAM-R and SLEDAI are responsive. SLAM-R is consistently, although moderately, more responsive than SLEDAI. All 5 methods of evaluating responsiveness yielded a consistent ranking of disease activity measures., Conclusion: SLAM-R and SLEDAI are responsive measures of lupus activity. SLAM-R appears to be more responsive than SLEDAI.

Objective: To identify concerns and learning interests of patients with arthritis., Methods: A questionnaire was developed, pilot tested, and then used to evaluate 197 patients with arthritis, including osteoarthritis (OA) (n = 41), rheumatoid arthritis (RA) (n = 57), back disease (n = 55), systemic lupus erythematosus (n = 27), and systemic sclerosis (SSc) (n = 17). Twenty concerns and 12 learning interests were rated. Questionnaires were also administered to assess physical disability (Health Assessment Questionnaire), psychological disability (Arthritis Impact Measurement Scales 2), and pain (visual analog scale). Participants addressed accessibility of health services, satisfaction with their physician, psychosocial needs, use of self-help groups, and behavioral strategies used to assist coping. Patients with RA, OA, and back disease, at both a community and a hospital center, were tested to assess whether concerns and learning interests differed based on site of treatment. Analytic methods included analysis of variance, factor analysis, and multiple linear regression., Results: There were no differences in concerns or learning interests based on treatment site. Between diagnostic groups, patients with SSc were more interested in learning about self-help groups. The most frequently reported concern was worsening of the illness. The majority of respondents were interested in learning more about topics that were illness specific. The physician was chosen as the preferred source of information, and the preferred format was in writing. On factor analysis, the 20 concerns were reduced to 5 factors: psychological, coping, medication, social, and financial. Three factors were identified for learning interests: the illness, traditional health management topics, and nontraditional health management topics. Stepwise multiple linear regression revealed predictors for the 5 concern and 3 learning interest factors. The concerns were best predicted by self-reported disease severity, physical disability, and psychological distress, while learning interests were best predicted by self-reported disease severity, pain, and self-help group membership., Conclusion: Concerns and learning interests of persons with arthritis did not differ based on the center of treatment or the diagnosis, but can be predicted by the level of pain and simple measures of disability. Better understanding of the relationship between health status and patient-perceived needs will result in improved patient-centered care.

In many medical experiments, data are collected across time, over a number of similar trials, or over a number of experimental units. As is the case of neuron spike train studies, these data may be in the form of counts of events per unit of time. These counts may be correlated within each trial. It is often of interest to know if the introduction of an intervention, such as the application of a stimulus, affects the distribution of the counts over the course of the experiment. In such investigations, each trial generates a sequence of data that may or may not contain a change in distribution at some point in time. Each sequence of integer counts can be viewed as arising from a Poisson process and are therefore independently distributed or as an integer-valued time series that allows for correlations between these counts. The main aim of this paper is to show how the ensemble of sample paths may be used to make inference about the distribution of the instantaneous times of change in a given population. This will be accomplished using a Bayesian hierarchical model for these change-points in time. A bonus of these models is they also allow for inference about the probability of a change in each unit and the magnitude of the effects, if any. The use of such change-point models on integer-valued time series is illustrated on neuron spike train data, although the methods can be applied to other situations where integer-valued processes arise.

Objective: To explore the relationship between patients' systemic lupus erythematosus (SLE) activity and physicians' decision to treat with steroids or alternative medication., Methods: Baseline information and clinical status was extracted from case histories of 30 patients with lupus and represented in clinical vignettes. These vignettes were then mailed to 60 physicians (rheumatologists and immunologists with experience in the treatment of lupus), asking them in each case whether they would initiate treatment or not. The relationship between the 38 complete responses and the SLE Activity Measure (SLAM-R) and SLE Disease Activity Index (SLEDAI) lupus activity scores was analyzed using a general additive model., Results: SLE disease activity measured by SLAM-R or SLEDAI is a significant predictor (p < 0.0001) of physicians' decision to initiate treatment for patients with lupus. Variation between physicians was observed but was mostly due to a few outliers. Some other variations remained unexplained by patients' SLE disease activity, damage, or by specific organ involvement., Conclusion: We present reference tables and curves for research that may be used as a basis to derive standardized quantitative criteria for entry in clinical trials. More research is needed on how these tools can be used by clinicians to guide them in their decision to treat or not.

Current understanding of the impact of lipids and other risk factors on coronary heart disease is largely based on the results of parametric multiple regression analyses of large prospective studies. To assess the potential impact of the a priori assumption of linearity of continuous risk factors on the results of parametric analyses, the authors completed a secondary analysis of the Lipid Research Clinics Prevalence and Follow-up Studies (1972-1987) data using an assumption-free nonparametric modeling approach. The effects of total serum cholesterol and the ratio of total serum cholesterol to high density lipoprotein cholesterol, adjusted for common risk factors, were estimated using a smoothing spline method available in the generalized additive model extension of the multiple logistic regression. The data set included 2,512 men in the random sample of the Lipid Research Clinics study who did not take lipid-lowering medications. During the median follow-up of 12.6 years, 94 coronary heart disease deaths occurred. The generalized additive model fits the effects of total serum cholesterol (p < 0.01) and the ratio of total serum cholesterol to high density lipoprotein cholesterol (p < 0.02) significantly better than the parametric logistic regression. Validation studies confirmed that, among new observations arising from the same population, generalized additive model estimates predicted outcomes better than the parametric estimates. Nonlinear effects of both lipid measures were robust and may be clinically important. The authors conclude that the linearity assumption inherent in parametric models may result in biased estimates of the effects of total serum cholesterol on coronary heart disease mortality and recommend that their findings be verified in a nonparametric analysis of data from another large prospective study.

The methodology of RECursive Partition and AMalgamation (RECPAM) previously presented in Parts I and II (A. Ciampi et al., Computer. Methods Progr. Biomed. 26 (1988) 239-256 and 30 (1989) 283-296) pursues its development with an application to predict long-term effects of a disease given a set of clinical information measured at the time of illness. This paper illustrates how RECPAM deals with a situation typical in Medical Informatics applied to data on Haemophilus influenzae type b meningitis.

We analyzed the risk of developing insulin-dependent diabetes mellitus (IDDM) in 411 siblings of patients with IDDM. We found that siblings who had a positive test for antibodies against islet cells (ICA) at the time of diagnosis of the index case had a higher risk of developing IDDM than did those who had negative tests. However, of the ten siblings who developed IDDM, only four were positive at the initial testing. The period of time elapsing from a negative test at screening to a positive test at diagnosis varied but was less than one year in one child. Two of the ten siblings who developed IDDM had negative tests both at screening and at diagnosis. Amongst siblings who were negative at the initial screening, those in whom the index case was diagnosed at a young age had a higher risk of developing IDDM than did those in whom the index case was diagnosed at an older age. The age of the sibling at the time of screening, the sex of the sibling, and a positive family history (one which includes in addition to the index case one or more first-degree relatives with IDDM) did not confer increased risk. Our data suggest that screening for ICA will have to be done often and will have to be continued into adult life in order to identify the 70-80% of diabetics who will be positive at some time in the evolution of their disease.

Background: Previous data on the consequences of Haemophilus influenzae type b meningitis for school-age children have been inconsistent, and much of the information on risk factors has been inconclusive. The present study was designed to evaluate the sequelae of this disease with a protocol for the comprehensive assessment of neuropsychological function., Methods: Ninety-seven school-age children (mean age, 9.6 years), each of whom had a school-age sibling, were recruited from a survey of the medical records of 519 children treated for H. influenzae type b meningitis between 1972 and 1984 (at a mean age of 17 months) at the children's hospitals of Toronto, Ottawa, and Montreal. Of the 97 children, 41 had had an acute neurologic complication. Sequelae were assessed by comparing the index children with their nearest siblings on the basis of standardized measures of cognitive, academic, and behavioral status., Results: Only 14 children (14 percent) had persisting neurologic sequelae: sensorineural hearing loss in 11 (unilateral in 6 and bilateral in 5), seizure disorder in 2, and hemiplegia and mental retardation in 1. Although the total sample of index children scored slightly below the siblings in reading ability, the 56 children without acute-phase neurologic complications (58 percent) were indistinguishable from their siblings on all measures. The differences between the groups were small even for the 41 pairs in which the index child had had an acute neurologic complication (mean full-scale IQ, 102 for the index children vs. 109 for the siblings). Sequelae were also associated with lower socioeconomic status and a lower ratio of glucose in cerebrospinal fluid to that in blood at the time of the meningitis. Behavioral problems were more prominent in index boys than index girls and in those who were older at the time of testing, but sex and age were not related to cognitive or academic sequelae., Conclusions: We find a favorable prognosis for the majority of children who are treated for meningitis caused by H. influenzae type b.