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Biomedical subjects

Michal Abrahamowicz

Publications and source records attributed to Michal Abrahamowicz.

At least 19 recordsLinked to original sources
PubMed2007

Joint estimation of time-dependent and non-linear effects of continuous covariates on survival.

In order to yield more flexible models, the Cox regression model, lambda(t;x) = lambda(0)(t)exp(betax), has been generalized using different non-parametric model estimation techniques. One generalization is the relaxation of log-linearity in x, lambda(t;x) = lambda(0)(t)exp[r(x)]. Another is the relaxation of the proportional hazards assumption, lambda(t;x) = lambda(0)(t)exp[beta(t)x]. These generalizations are typically considered independently of each other. We propose the product model, lambda(t;x) = lambda(0)(t)exp[beta(t)r(x)] which allows for joint estimation of both effects, and investigate its properties. The functions describing the time-dependent beta(t) and non-linear r(x) effects are modelled simultaneously using regression splines and estimated by maximum partial likelihood. Likelihood ratio tests are proposed to compare alternative models. Simulations indicate that both the recovery of the shapes of the two functions and the size of the tests are reasonably accurate provided they are based on the correct model. By contrast, type I error rates may be highly inflated, and the estimates considerably biased, if the model is misspecified. Applications in cancer epidemiology illustrate how the product model may yield new insights about the role of prognostic factors.

Aged↗
PubMed2006

Assessment of health-related quality of life in arthritis: conceptualization and development of five item banks using item response theory.

BACKGROUND: Modern psychometric methods based on item response theory (IRT) can be used to develop adaptive measures of health-related quality of life (HRQL). Adaptive assessment requires an item bank for each domain of HRQL. The purpose of this study was to develop item banks for five domains of HRQL relevant to arthritis. METHODS: About 1,400 items were drawn from published questionnaires or developed from focus groups and individual interviews and classified into 19 domains of HRQL. We selected the following 5 domains relevant to arthritis and related conditions: Daily Activities, Walking, Handling Objects, Pain or Discomfort, and Feelings. Based on conceptual criteria and pilot testing, 219 items were selected for further testing. A questionnaire was mailed to patients from two hospital-based clinics and a stratified random community sample. Dimensionality of the domains was assessed through factor analysis. Items were analyzed with the Generalized Partial Credit Model as implemented in Parscale. We used graphical methods and a chi-square test to assess item fit. Differential item functioning was investigated using logistic regression. RESULTS: Data were obtained from 888 individuals with arthritis. The five domains were sufficiently unidimensional for an IRT-based analysis. Thirty-one items were deleted due to lack of fit or differential item functioning. Daily Activities had the narrowest range for the item location parameter (-2.24 to 0.55) and Handling Objects had the widest range (-1.70 to 2.27). The mean (median) slope parameter for the items ranged from 1.15 (1.07) in Feelings to 1.73 (1.75) in Walking. The final item banks are comprised of 31-45 items each. CONCLUSION: We have developed IRT-based item banks to measure HRQL in 5 domains relevant to arthritis. The items in the final item banks provide adequate psychometric information for a wide range of functional levels in each domain.

Activities of Daily Living↗
PubMed2006

Classification of patterns of delirium severity scores over time in an elderly population.

OBJECTIVES: To describe and classify individual trajectories of 15-day changes in delirium severity. METHODS: A longitudinal hospital-based study was carried out with 230 medical inpatients aged 65 and over admitted to St Mary's Hospital in Montreal, Canada, between 1996 and 1999, diagnosed with delirium at enrollment, and who had at least four measurements of delirium severity during the next 15 days. Delirium severity was assessed using the Delirium Index (DI). To classify patients' individual trajectories, we applied a new method that relies on principal factor analysis and cluster analysis. We used multiple linear regression to investigate if clusters were associated with DI scores measured at an 8-week follow-up. Multivariable Cox's proportional hazards regression was used to assess whether the clusters were associated with survival over the next 12 months. RESULTS: Individual patterns were classified into five clusters: Steady (n = 89, 38.9%), Fluctuating (n = 36, 15.7%), Worsening (n = 15, 6.6%), Fast Improve-ment (n = 26, 11.3%), and Slow Improvement (n = 63, 27.5%). The Fast Improvement cluster had much lower prevalence of dementia (38.5% vs. 55.6% to 77.8% in other clusters, p = 0.003). Subjects whose 2-week patterns were classified as Fast or Slow Improvement had a significantly lower DI at 8 weeks than those in the Steady or Fluctuating clusters. The Worsening cluster had the largest percentage of deaths. The Fast Improvement and Worsening clusters initially had a high risk of death in the first 2 weeks (adjusted relative risks of approximately 3 and 6, respectively) but that risk decreased rapidly thereafter. CONCLUSION: Two-week trajectories of delirium severity were associated with short-term mortality and delirium severity at 8-week follow-up.

Aged↗
PubMed2006

Modeling cumulative dose and exposure duration provided insights regarding the associations between benzodiazepines and injuries.

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.

Accidental Falls↗
PubMed2006

Bronchial artery embolization in adults with cystic fibrosis: impact on the clinical course and survival.

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.

Adult↗
PubMed2006

Predictors of health status in women with fibromyalgia: a prospective study.

Although cross-sectional studies have identified correlates of dysfunction in fibromyalgia (FM) patients (e.g., psychological distress and pain), predictors of health status have not been previously investigated using a longitudinal research design. We gathered data from 156 women who met American College of Rheumatology criteria for primary FM recruited from both tertiary care and community settings. Stepwise multiple linear regression analysis indicated that poorer health status (p < .0001) and more comorbidity (p = .0089) at baseline were predictors of poorer health status 6 months later. After controlling for these covariates, psychological distress contributed significantly to the model (p = .01). There was a trend indicating that palliative coping styles (i.e., self-care, energy conservation) altered the impact of pain on 6-month health status (p = .06). These findings highlight the need for multidisciplinary interventions that target psychological distress, coping, and comorbidity in patients with FM.

Adult↗
PubMed2006

Adherence during an individualized home based 12-week exercise program in women with fibromyalgia.

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.

Attitude to Health↗
PubMed2005

Comparison of Cox's and relative survival models when estimating the effects of prognostic factors on disease-specific mortality: a simulation study under proportional excess hazards.

In many prognostic studies focusing on mortality of persons affected by a particular disease, the cause of death of individual patients is not recorded. In such situations, the conventional survival analytical methods, such as the Cox's proportional hazards regression model, do not allow to discriminate the effects of prognostic factors on disease-specific mortality from their effects on all-causes mortality. In the last decade, the relative survival approach has been proposed to deal with the analyses involving population-based cancer registries, where the problem of missing information on the cause of death is very common. However, some questions regarding the ability of the relative survival methods to accurately discriminate between the two sources of mortality remain open. In order to systematically assess the performance of the relative survival model proposed by Esteve et al., and to quantify its potential advantages over the Cox's model analyses, we carried out a series of simulation experiments, based on the population-based colon cancer registry in the French region of Burgundy. Simulations showed a systematic bias induced by the 'crude' conventional Cox's model analyses when individual causes of death are unknown. In simulations where only about 10 per cent of patients died of causes other than colon cancer, the Cox's model over-estimated the effects of male gender and oldest age category by about 17 and 13 per cent, respectively, with the coverage rate of the 95 per cent CI for the latter estimate as low as 65 per cent. In contrast, the effect of higher cancer stages was under-estimated by 8-28 per cent. In contrast to crude survival, relative survival model largely reduced such problems and handled well even such challenging tasks as separating the opposite effects of the same variable on cancer-related versus other-causes mortality. Specifically, in all the cases discussed above, the relative bias in the estimates from the Esteve et al.'s model was always below 10 per cent, with the coverage rates above 81 per cent.

Aged↗
PubMed2005

The development and evaluation of an integrated electronic prescribing and drug management system for primary care.

OBJECTIVE: To develop and evaluate the acceptability and use of an integrated electronic prescribing and drug management system (MOXXI) for primary care physicians. DESIGN: A 20-month follow-up study of MOXXI (Medical Office of the XXIst Century) implementation in 28 primary care physicians and 13,515 consenting patients. MEASUREMENT: MOXXI was developed to enhance patient safety by integrating patient demographics, retrieving active drugs from pharmacy systems, generating an automated problem list, and providing electronic prescription, stop order, automated prescribing problem alerts, and compliance monitoring functions. Evaluation of technical performance, acceptability, and use was conducted using audit trails, questionnaires, standardized tasks, and information from comprehensive health insurance databases. RESULTS: Perceived improvements in continuity of care and professional autonomy were associated with physicians' expected use of MOXXI. Physician speed in using MOXXI improved substantially in the first three months; however, only the represcribing function was faster using MOXXI than by handwritten prescription. Physicians wrote electronic prescriptions in 36.9 per 100 visits and reviewed the patient's drug profile in 12.6 per 100 visits. Physicians rated printed prescriptions, the current drug list, and the represcribing function as the most beneficial aspects of the system. Physicians were more likely to use the drug profile for patients who used more medication, made more emergency department visits, had more prescribing physicians, and lower continuity of care. CONCLUSION: Primary care physicians believed an integrated electronic prescribing and drug management system would improve continuity of care, and they were more likely to use the system for patients with more complex, fragmented care.

Attitude of Health Personnel↗
PubMed2005

Effect of a community oriented problem based learning curriculum on quality of primary care delivered by graduates: historical cohort comparison study.

OBJECTIVE: To assess whether the transition from a traditional curriculum to a community oriented problem based learning curriculum at Sherbrooke University is associated with the expected improvements in preventive care and continuity of care without a decline in diagnosis and management of disease. DESIGN: Historical cohort comparison study. SETTING: Sherbrooke University and three traditional medical schools in Quebec, Canada. PARTICIPANTS: 751 doctors from four graduation cohorts (1988-91); three before the transition to community based problem based learning (n = 600) and one after the transition (n = 151). OUTCOME MEASURES: Annual performance in preventive care (mammography screening rate), continuity of care, diagnosis (difference in prescribing rates for specific diseases and relief of symptoms), and management (prescribing rate for contraindicated drugs) assessed using provincial health databases for the first 4-7 years of practice. RESULTS: After transition to a community oriented problem based learning curriculum, graduates of Sherbrooke University showed a statistically significant improvement in mammography screening rates (55 more women screened per 1000, 95% confidence interval 10.6 to 99.3) and continuity of care (3.3% more visits coordinated by the doctor, 0.9% to 5.8%) compared with graduates of a traditional medical curriculum. Indicators of diagnostic and management performance did not show the hypothesised decline. Sherbrooke graduates showed a significant fourfold increase in disease specific prescribing rates compared with prescribing for symptom relief after the transition. CONCLUSION: Transition to a community oriented problem based learning curriculum was associated with significant improvements in preventive care and continuity of care and an improvement in indicators of diagnostic performance.

Aged↗
PubMed2005

Maintenance of exercise in women with fibromyalgia.

OBJECTIVE: To identify predictors of maintenance of exercise for women with fibromyalgia (FM). METHODS: Women with FM who had been randomized to the exercise arm of a clinical trial were studied prospectively during and 3 months following treatment. Subjects completed exercise logs weekly and returned the data via postal mail. Outcome variables were duration of aerobic and stretching exercises. Two separate multivariate models for longitudinal data were built with adjustment for in-treatment adherence and time. Pretreatment characteristics (self efficacy, pain, disability, stress, exercise barriers and benefits, and age) and changes during treatment (pain, disability, stress, and exercise barriers and benefits) were considered potential predictors of exercise maintenance. RESULTS: Stretching significantly decreased in the 3 months following treatment. High stress at baseline and increases in stress during treatment were associated with poor maintenance of stretching. Disability at baseline (measured with the Fibromyalgia Impact Questionnaire), an increase in barriers to exercise during treatment, and increases in upper-body pain during treatment were associated with worse maintenance of aerobic exercise in the 3 months following treatment. CONCLUSION: The maintenance of an exercise program in women with FM appears to be contingent on being able to deal with stress, pain, barriers to exercise, and disability.

Exercise↗
PubMed2005

Survival bias associated with time-to-treatment initiation in drug effectiveness evaluation: a comparison of methods.

The authors compared five methods of studying survival bias associated with time-to-treatment initiation in a drug effectiveness study using medical administrative databases (1996-2002) from Quebec, Canada. The first two methods illustrated how survival bias could be introduced. Three additional methods were considered to control for this bias. Methods were compared in the context of evaluating statins for secondary prevention in elderly patients post-acute myocardial infarction who initiated statins within 90 days after discharge and those who did not. Method 1 that classified patients into users and nonusers at discharge resulted in an overestimation of the benefit (38% relative risk reduction at 1 year). In method 2, following users from the time of the first prescription and nonusers from a randomly selected time between 0 and 90 days attenuated the effect toward the null (10% relative risk reduction). Method 3 controlled for survival bias by following patients from the end of the 90-day time window; however, it suffered a major loss of statistical efficiency and precision. Method 4 matched prescription time distribution between users and nonusers at cohort entry. Method 5 used a time-dependent variable for treatment initiation. Methods 4 and 5 better controlled for survival bias and yielded similar results, suggesting a 20% risk reduction of recurrent myocardial infarction or death events.

Aged↗
PubMed2005

Effectiveness of statins for secondary prevention in elderly patients after acute myocardial infarction: an evaluation of class effect.

BACKGROUND: Clinical trials have shown the benefits of statins after acute myocardial infarction (AMI). However, it is unclear whether different statins exert a similar effect in reducing the incidence of recurrent AMI and death when used in clinical practice. METHODS: We conducted a retrospective cohort study (1997-2002) to compare 5 statins using data from medical administrative databases in 3 provinces (Quebec, Ontario and British Columbia). We included patients aged 65 years and over who were discharged alive after their first AMI-related hospital stay and who began statin treatment within 90 days after discharge. The primary end point was the combined outcome of recurrent AMI or death from any cause. The secondary end point was death from any cause. Adjusted hazard ratios (HRs) for each statin compared with atorvastatin as the reference drug were estimated using Cox proportional hazards regression analysis. RESULTS: A total of 18,637 patients were prescribed atorvastatin (n = 6420), pravastatin (n = 4480), simvastatin (n = 5518), lovastatin (n = 1736) or fluvastatin (n = 483). Users of different statins showed similar baseline characteristics and patterns of statin use. The adjusted HRs (and 95% confidence intervals) for the combined outcome of AMI or death showed that each statin had similar effects when compared with atorvastatin: pravastatin 1.00 (0.90-1.11), simvastatin 1.01 (0.91-1.12), lovastatin 1.09 (0.95-1.24) and fluvastatin 1.01 (0.80-1.27). The results did not change when death alone was the end point, nor did they change after adjustment for initial daily dose or after censoring of patients who switched or stopped the initial statin treatment. INTERPRETATION: Our results suggest that, under current usage, statins are equally effective for secondary prevention in elderly patients after AMI.

Aged↗
PubMed2005

Comparison of nested case-control and survival analysis methodologies for analysis of time-dependent exposure.

BACKGROUND: Epidemiological studies of exposures that vary with time require an additional level of methodological complexity to account for the time-dependence of exposure. This study compares a nested case-control approach for the study of time-dependent exposure with cohort analysis using Cox regression including time-dependent covariates. METHODS: A cohort of 1340 subjects with four fixed and seven time-dependent covariates was used for this study. Nested case-control analyses were repeated 100 times for each of 4, 8, 16, 32, and 64 controls per case, and point estimates were compared to those obtained using Cox regression on the full cohort. Computational efficiencies were evaluated by comparing central processing unit times required for analysis of the cohort at sizes 1, 2, 4, 8, 16, and 32 times its initial size. RESULTS: Nested case-control analyses yielded results that were similar to results of Cox regression on the full cohort. Cox regression was found to be 125 times slower than the nested case-control approach (using four controls per case). CONCLUSIONS: The nested case-control approach is a useful alternative for cohort analysis when studying time-dependent exposures. Its superior computational efficiency may be particularly useful when studying rare outcomes in databases, where the ability to analyze larger sample sizes can improve the power of the study.

Aged↗
PubMed2005

The McGill ingestive skills assessment predicts time to death in an elderly population with neurogenic dysphagia: preliminary evidence.

The McGill Ingestive Skills Assessment (MISA) is a new assessment tool which quantifies the ingestive process by scoring a meal observation. The reliability and the construct validity of the MISA have been documented. However, establishment of the ability of the MISA to predict health outcomes related to feeding difficulties would support its applicability in research and in clinical settings. Seventy-three participants of a large-scale reliability and validity study were followed for up to 563 days following evaluation with the MISA. The date of the first pulmonary infection and the date and cause of death where applicable were obtained from medical records. Individuals with no incident of pulmonary infection and who were not deceased were "censored" at the date of followup. Survival analyses revealed that the MISA scores are predictive of death using a Cox proportional hazards model, and of time to pulmonary infection using a flexible model. Scores on the Solid Ingestion and Self-feeding scales are predictive of death using the Cox model, and the Texture Management scale is predictive of death using the flexible model. This effect remains statistically significant even when MISA scores are adjusted for the participant's age. These findings support the validity of the MISA for use with elderly individuals with neurogenic ingestive skill loss residing in long-term care facilities.

Adult↗
PubMed2005

Are indirect utility measures reliable and responsive in rheumatoid arthritis patients?

BACKGROUND: Preference-based, generic measures are increasingly being used to measure quality of life and as sources for quality weights in the estimation of Quality Adjusted Life Years (QALYs) in rheumatoid arthritis (RA). However, among the most commonly used instruments (the Health Utilities Index 2 and 3 [HUI2 and HUI3], the EuroQoL-5D [EQ-5D], and the Short Form-6D [SF-6D], there has been little comparative research. Therefore, we examined the reliability and responsiveness of these measures and the Rheumatoid Arthritis Quality of Life (RAQoL) and the Health Assessment Questionnaire (HAQ) in a sample of RA patients. MAJOR FINDINGS: Test-retest reliability was acceptable for all of the instruments with the exception of the EQ-5D. Using two external criteria to define change (a patient transition question and categories of the patient global assessment of disease activity VAS), the RAQoL was the most responsive of the instruments. For the indirect utility instruments, the HUI3 and the SF-6D were the most responsive for measuring positive change. On average, for patients whose RA improved, the absolute change was highest for the HUI3. CONCLUSIONS: The HUI3 and the SF-6D appear to be the most responsive of the preference-based instruments in RA. However, differences in the magnitude of the absolute change scores have important implications for cost-effectiveness analyses.

Arthritis, Rheumatoid↗
PubMed2005

A 5-year prospective assessment of the risk associated with individual benzodiazepines and doses in new elderly users.

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.

Aged↗
PubMed2005

Modifiable risk factors associated with clearance of type-specific cervical human papillomavirus infections in a cohort of university students.

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.

Adolescent↗