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Biomedical subjects

J Avorn

Publications and source records attributed to J Avorn.

At least 19 recordsLinked to original sources
PubMed2006

Patterns of cardiovascular risk in rheumatoid arthritis.

BACKGROUND: Although it is known that rheumatoid arthritis is associated with an increased risk of cardiovascular disease (CVD), the pattern of this risk is not clear. This study investigated the relative risk of myocardial infarction, stroke and CVD mortality in adults with rheumatoid arthritis compared with adults without rheumatoid arthritis across age groups, sex and prior CVD event status. METHODS: We conducted a cohort study among all residents aged >or=18 years residing in British Columbia between 1999 and 2003. Residents who had visited the doctor at least thrice for rheumatoid arthritis (International Classification of Disease = 714) were considered to have rheumatoid arthritis. A non-rheumatoid arthritis cohort was matched to the rheumatoid arthritis cohort by age, sex and start of follow-up. The primary composite end point was a hospital admission for myocardial infarction, stroke or CVD mortality. RESULTS: 25 385 adults who had at least three diagnoses for rheumatoid arthritis during the study period were identified. During the 5-year study period, 375 patients with rheumatoid arthritis had a hospital admission for myocardial infarction, 363 had a hospitalisation for stroke, 437 died from cardiovascular causes and 1042 had one of these outcomes. The rate ratio for a CVD event in patients with rheumatoid arthritis was 1.6 (95% confidence interval (CI) 1.5 to 1.7), and the rate difference was 5.7 (95% CI 4.9 to 6.4) per 1000 person-years. The rate ratio decreased with age, from 3.3 in patients aged 18-39 years to 1.6 in those aged >or=75 years. However, the rate difference was 1.2 per 1000 person-years in the youngest age group and increased to 19.7 per 1000 person-years in those aged >or=75 years. Among patients with a prior CVD event, the rate ratios and rate differences were not increased in rheumatoid arthritis. CONCLUSIONS: This study confirms that rheumatoid arthritis is a risk factor for CVD events and shows that the rate ratio for CVD events among subjects with rheumatoid arthritis is highest in young adults and those without known prior CVD events. However, in absolute terms, the difference in event rates is highest in older adults.

Adolescent↗
PubMed2006

A randomized controlled trial of mailed osteoporosis education to older adults.

INTRODUCTION: Osteoporosis represents a growing public health concern; however, current rates of management are sub-optimal. The aim of our study was to assess, in a randomized controlled trial, the effect of a mailed educational intervention on older adults' knowledge, attitudes, and preventive behaviors regarding osteoporosis. The setting was a large publicly funded state pharmacy benefits program. The patients were 31,715 Medicare beneficiaries from Pennsylvania who participated in a drug benefits program for low-to-moderate income elderly people. METHODS: All women aged over 65 years, and all men and women with a history of fracture or long-term oral use of glucocorticoid, were included. Approximately half of the participants (intervention group) were randomly selected to receive three mailings aimed at improving knowledge of osteoporosis and enhancing preventive activities, such as using calcium and vitamin D, reducing fall risks in the home, obtaining a bone mineral density (BMD) test, and taking medications when necessary. The other participants did not receive the intervention mailings and served as controls. We surveyed a sample of intervention and control subjects to determine the effects of the intervention on knowledge, attitudes, self-efficacy (confidence in one's ability to perform specific activities), and behavior regarding osteoporosis prevention and treatment. Six hundred randomly selected participants in the intervention group and an equal number in the control group were invited to participate. RESULTS: Twenty-six had died and 636 of the remaining 1,185 (54%) completed the survey. Respondents and non-respondents did not differ significantly with respect to measured sociodemographic factors. All scales had good reliability (all Cronbach's alphas>0.65). Knowledge of osteoporosis was generally very good and did not differ between intervention (mean=65% correct responses) and control subjects (mean=67% correct; P=0.4). Perceived susceptibility to osteoporosis was relatively high and similar across groups (P=0.4). Self-efficacy for participating in osteoporosis prevention and treatment was very strong in both the intervention (mean=4.3 on a 0-5 scale) and control (mean=4.2, P=0.03) groups . On average, subjects in the intervention group reported participating in 3.5 of 6 preventive osteoporosis activities compared with 3.4 in the control group (P=0.5). CONCLUSIONS: Compared with the controls, a mailed educational intervention for osteoporosis was not associated with better knowledge, higher perceived susceptibility, or performance of preventive measures among the at-risk older adults that we studied. The intervention group demonstrated a small increase in self-efficacy. More intensive patient interventions or intervention aimed at other aspects of the care process may be required to bring about changes that lead to a reduction in fractures.

Aged↗
PubMed2005

A cost minimization model for the treatment of minor bleeding episodes in patients with haemophilia A and high-titre inhibitors.

Treatment of acute bleeding episodes in patients with haemophilia A and inhibitory antibodies to factor VIII (FVIII) most often involves the use of bypassing haemostatic agents, such as activated prothrombin complex concentrates (aPCC) or recombinant factor VIIa (rFVIIa). We constructed a cost minimization model to compare the costs of initial treatment with aPCC vs. rFVIIa in the home treatment of minor bleeding episodes. We developed a clinical scenario describing such a case and presented it to a panel of US haemophilia specialists. For each product class, we asked panellists to provide dosing regimens required to achieve complete resolution of a minor haemarthrosis in a child with high-titre inhibitors, and for the probabilities of success at two time points (8-12 and 24 h). Consensus among the panellists was refined by a second round of the process, and the median values resulting were used as inputs to a decision analysis model. Sensitivity analyses were conducted to determine threshold values for key variables. The base case model found that initial treatment with aPCC would result in a mean cost per episode of 21 000 dollars, compared with 33 400 dollars for initial treatment with rFVIIa. Sensitivity analyses over a range of clinically plausible values for cost, dosing, and efficacy did not change the selection of aPCC as the dominant strategy.

Autoantibodies↗
PubMed2004

The economic impact of factor VIII inhibitors in patients with haemophilia.

The impact on the cost of care for haemophilia patients with inhibitors is not well defined. To quantify the effect on health care expenditures associated with inhibitors to factor VIII (FVIII) or FIX, we conducted a retrospective cohort study examining product use and outcomes in adult and paediatric haemophilia patients with and without inhibitors. Twelve patients with inhibitors to FVIII or FIX (cases) identified in the haemophilia surveillance system (HSS) at two centres were matched on age, severity of haemophilia, and treatment centre to haemophilia patients without inhibitors. Patients with HIV or significant liver disease were excluded from the study. All eligible non-inhibitor control patients were selected for inclusion in the study, resulting in a total of 28 controls. We then tracked product usage and hospitalizations from programme entry until 1998 or loss to follow-up, producing a total database of 184 person-years of experience. A descriptive matched analysis was conducted to examine annual differences in the cost of product used and hospitalizations. We found that the median cost for factor products among haemophilia patients with inhibitors was $55,853/year, $2,760 less than comparable haemophilia patients without inhibitors. The median number of hospitalizations per year was 1.0 for both inhibitor and non-inhibitor patients and the median number of days hospitalized was virtually the same. Although these findings do not appear to support the belief that there is a substantial increase in the cost of care for haemophilia patients with inhibitors, it does document that a few outlier patients can drive the cost of treatment for this disease. As the largest component of the cost of care is that of factor concentrate, it becomes imperative in the current health care environment to better define the true costs and benefits of treatments designed to eradicate or manage inhibitors. A careful cost accounting of immune tolerance induction (ITI) and other therapeutic strategies, taking into account successes and failures and duration and intensity of therapy, should help to better define the costs and benefits of such approaches. Methods to identify high cost inhibitor patients should be developed so that these strategies may be targeted to appropriate candidates.

Adolescent↗
PubMed2003

Undertreatment of hypercholesterolaemia: a population-based study.

AIMS: To assess the level of undertreatment of hypercholesterolaemia in the general population, taking intra-person variability in serum cholesterol concentrations into account, and to identify determinants of undertreatment of hypercholesterolaemia. METHODS: In this cross-sectional study, data from two population-based surveys on cardiovascular disease risk factors conducted between 1987 and 1997 in the Netherlands were used. For all 64 757 respondents aged 20-59 years, treatment eligibility for lipid-lowering drug use was established according to the Dutch Cholesterol Consensus. Multivariate logistic models were used to identify determinants of undertreatment. RESULTS: During the study period, 56.8% of the study population had undesirable cholesterol concentrations (serum total cholesterol> 5 mmol l(-1)) and 5.5% of those were eligible for pharmacological treatment based on their absolute risk of coronary heart disease. Of those eligible for pharmacological treatment, 16.3% were treated, and 19.6% of those treated had their serum total cholesterol concentration controlled. Only 3.2% of those eligible for pharmacological treatment were both treated and controlled. We identified several determinants for undertreatment, e.g. male gender and younger age for primary prevention and female gender and older age for secondary prevention. Treatment has improved slightly in more recent years. CONCLUSIONS: Over 95% of the population eligible for the pharmacological treatment of hypercholesterolaemia was either untreated or was uncontrolled. To decrease undertreatment, identification of high-risk patients should be increased. Those who are treated with lipid-lowering medication could further benefit from more aggressive treatment, especially with statins.

Adult↗
PubMed2002

Porcine factor VIII: pharmacoeconomics of inhibitor therapy.

The treatment of acquired haemophilia is characteristically exceedingly expensive and thus a cost-benefit analysis of the several available treatment strategies is urgently needed. To address this issue, decision-analysis techniques were used to construct a cost-minimization model to compare the cost of treatment with porcine factor VIII (pFVIII), human FVIII (hFVIII) or an activated prothrombin complex concentrate (APCC). This model was based upon the results of a comprehensive literature search of all relevant clinical studies and case series. To supplement these data, a panel of haemophilia specialists was presented with a clinical scenario describing an acquired haemophilia patient with an acute haemorrhage in whom the human and porcine inhibitor titres were initially unknown. Based on this scenario and on their own clinical experience, the expert panel assessed the applicability of the model as initially constructed, assigned probabilities of success to each treatment and recommended appropriate initial dosing and follow-up regimens. This information was incorporated into the model and a simulation was conducted from which the costs of care were calculated. Sensitivity analyses were then conducted on all parameters. The results of the model show that treatment initiated with pFVIII would be more cost effective compared with treatment sequences initiated with an APCC or hFVIII, respectively. The model indicates that initial treatment with pFVIII in this scenario may be the preferred strategy clinically, as well as on economic grounds.

Algorithms↗
PubMed2001

Performance of comorbidity scores to control for confounding in epidemiologic studies using claims data.

Comorbidity is an important confounder in epidemiologic studies. The authors compared the predictive performance of comorbidity scores for use in epidemiologic research with administrative databases. Study participants were British Columbia, Canada, residents aged >or=65 years who received angiotensin-converting enzyme inhibitors or calcium channel blockers at least once during the observation period. Six scores were computed for all 141,161 participants during the baseline year (1995-1996). Endpoints were death and health care utilization during a 12-month follow-up (1996-1997). Performance was measured by using the c statistic ranging from 0.5 for chance prediction of outcome to 1.0 for perfect prediction. In logistic regression models controlling for age and gender, four scores based on the International Classification of Diseases, Ninth Revision (ICD-9) generally performed better at predicting 1-year mortality (c = 0.771, c = 0.768, c = 0.745, c = 0.745) than medication-based Chronic Disease Score (CDS)-1 and CDS-2 (c = 0.738, c = 0.718). Number of distinct medications used was the best predictor of future physician visits (R(2) = 0.121) and expenditures (R(2) = 0.128) and a good predictor of mortality (c = 0.745). Combining ICD-9 and medication-based scores improved the c statistics (1.7% and 6.2%, respectively) for predicting mortality. Generalizability of results may be limited to an elderly, predominantly White population with equal access to state-funded health care.

Aged↗
PubMed2001

Risk factors for adverse drug events among nursing home residents.

BACKGROUND: In a prospective study of nursing home residents, we found adverse drug events (ADEs) to be common, serious, and often preventable. To direct prevention efforts at high-risk residents, information is needed on resident-level risk factors. METHODS: Case-control study nested within a prospective study of ADEs among residents in 18 nursing homes. For each ADE, we randomly selected a control from the same home. Data were abstracted from medical records on functional status, medical conditions, and medication use. RESULTS: Adverse drug events were identified in 410 nursing home residents. Independent risk factors included being a new resident (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.5-5.2) and taking anti-infective medications (OR, 4.0; CI, 2.5-6.2), antipsychotics (OR, 3.2; CI, 2.1-4.9), or antidepressants (OR, 1.5; CI, 1.1-2.3). The number of regularly scheduled medications was associated with increased risk of ADEs; the OR associated with taking 5 to 6 medications was 2.0 (CI, 1.2-3.2); 7 to 8 medications, 2.8 (CI, 1.7-4.7); and 9 or more, 3.3 (CI, 1.9-5.6). Taking supplements or nutrients was associated with lower risk (OR, 0.42; CI, 0.27-0.63). Preventable ADEs occurred in 226 residents. Independent risk factors included taking opioid medications (OR, 6.6; CI, 2.3-19.3), antipsychotics (OR, 4.0; CI, 2.2-7.3), anti-infectives (OR, 3.0; CI, 1.6-5.8), antiepileptics (OR, 2.2; CI, 1.1-4.5), or antidepressants (OR, 2.0; CI, 1.1-3.5). Scores of 5 or higher on the Charlson Comorbidity Index were associated with increased risk of ADEs (OR, 2.6; CI, 1.1-6.0). The number of regularly scheduled medications was also a risk factor: the OR for 7 to 8 medications was 3.2 (CI, 1.4-6.9) and for 9 or more, 2.9 (CI, 1.3-6.8). Residents taking nutrients or supplements were at lower risk (OR, 0.27; CI, 0.14-0.50). CONCLUSIONS: It is possible to identify nursing home residents at high risk of having an ADE. Particular attention should be directed at new residents, those with multiple medical conditions, those taking multiple medications, and those taking psychoactive medications, opioids, or anti-infective drugs.

Aged↗
PubMed2001

Reducing prescribing of highly anticholinergic antidepressants for elderly people: randomised trial of group versus individual academic detailing.

OBJECTIVE: To compare the effect of individual educational visits versus group visits using academic detailing to discuss prescribing of highly anticholinergic antidepressants in elderly people. DESIGN: Randomised controlled trial with three arms (individual visits, group visits, and a control arm). SETTING: Southwest Netherlands. PARTICIPANTS: 190 general practitioners and 37 pharmacists organised in 21 peer review groups were studied using a database covering all prescriptions to people covered by national health insurance in the area (about 240 000). INTERVENTION: All general practitioners and pharmacists in both intervention arms were offered two educational visits. For physicians in groups randomised to the individual visit arm, 43 of 70 general practitioners participated; in the group visit intervention arm, five of seven groups (41 of 52 general practitioners) participated. MAIN OUTCOME MEASURES: Numbers of elderly people (>/=60 years) with new prescriptions of highly anticholinergic antidepressants and less anticholinergic antidepressants. RESULTS: An intention to treat analysis found a 26% reduction in the rate of starting highly anticholinergic antidepressants in elderly people (95% confidence interval -4% to 48%) in the individual intervention arm and 45% (8% to 67%) in the group intervention arm. The use of less anticholinergic antidepressants increased by 40% (6% to 83%) in the individual intervention arm and 29% (-7% to 79%) in the group intervention arm. CONCLUSIONS: Both the individual and the group visits decreased the use of highly anticholinergic antidepressants and increased the use of less anticholinergic antidepressant in elderly people. These approaches are practical means to improve prescribing by continuing medical education.

Aged↗
PubMed2001

Do the research goal and databases match? A checklist for a systematic approach.

To test the appropriateness of a given database for specific research questions, we designed a checklist starting with the definition of an ideal database. This ideal database contains all relevant data on patients, providers and services. It is safe and accessible, input is always accurate, continuity is guaranteed and linkage with other information is easy. Of course no such database exists. Still these features are often taken for granted, but highly influenced by organizational processes in healthcare and prioritization. Starting with the characteristics of an ideal database, one can systematically list the required aspects for research goals and compare these with the available systems. This checklist is used to address important aspects of administrative database research and ethical issues. The increasing possibility to misuse sensitive data needs to be discussed by researchers, administrators, individuals and society. This checklist can also be valuable to others to design or interpret studies based on claims databases.

Benchmarking↗
PubMed2001

Use of risk stratification to identify patients with unstable angina likeliest to benefit from an invasive versus conservative management strategy.

OBJECTIVES: This study was designed to determine whether patient characteristics collected at presentation can identify which patients benefit from immediate coronary angiography and revascularization. BACKGROUND: Risk stratification may offer a method for identifying which patients with unstable angina or non-Q-wave myocardial infarction (NQMI) are likeliest to benefit from invasive management strategies. METHODS: The analysis was based on data from a randomized controlled trial that enrolled 1,473 patients presenting with unstable angina or NQMI who were randomly assigned to an early invasive or early conservative (medical) management strategy. We constructed a risk-stratification score for each patient based on adjusted odds ratios for clinical variables likely to predict adverse outcomes. We stratified all trial subjects by their risk scores and studied the rates of death or myocardial infarction (MI) of the early invasive management strategy in each stratum. RESULTS: The final multivariate model included older age, ST segment depression on presentation, history of complicated angina before presentation, and elevation in baseline creatine kinase-MB fraction. Although patients with a higher risk score had an increased rate of death or MI within 42 days and 365 days (p < 0.001) in both management strategies, early invasive management for patients in the high and very high risk categories was associated with a lower rate of death or MI within 42 days compared with conservative management. No such benefit was seen in patients in the larger group of patients in the very low, low or moderate risk categories (p = 0.03 for the interaction between risk category and management assignment). CONCLUSIONS: Risk stratification may be an effective method for identifying those patients with unstable angina or NQMI most likely to benefit from early invasive management. Selective use of early invasive management can have a substantial impact in reducing morbidity and mortality in higher risk patients, but may not be warranted in lower risk patients.

Aged↗
PubMed2001

Antidepressant use and the risk of breast cancer: a non-association.

OBJECTIVE: Animal studies have suggested that some antidepressant medications may act as breast tumor promoters and recent epidemiologic studies of antidepressant use and breast cancer outcomes in humans have also reported such associations. DESIGN: Retrospective cohort study. STUDY POPULATION: 38,273 women who filled a prescription for any of a number of antidepressants and 32,949 who filled a prescription for any other medication during 1989-1991; all were > or =20, enrolled in Medicare, Medicaid or the Pharmaceutical Assistance to the Aged and Disabled (PAAD) programs of New Jersey, and free of evidence of breast cancer. DATA COLLECTION: Antidepressant use was assessed over a period lasting up to 24 months. Subjects were followed for a maximum of 7.5 years; those who had a first diagnosis of breast cancer in the New Jersey Cancer Registry at least 3 months after their index date were considered incident breast cancer cases. Other covariates, including demographic, clinical, and health care utilization variables were also assessed. MAIN OUTCOME OF INTEREST: Adjusted hazard ratio (HR) of developing breast cancer, based on multivariable proportional hazards models. RESULTS: Use of antidepressants was unrelated to the development of breast cancer (adjusted HR = 1.04; 95% CI 0.87-1.25). No elevated risks were found for specific antidepressants, including agents found to be breast tumor promoters in animal studies, as well as drugs thought to be associated with breast cancer in prior epidemiologic studies. There was no suggestion that breast cancer risks were increased with more intensive use of antidepressants or that antidepressant use is associated with a more severe stage of cancer at diagnosis. CONCLUSIONS: Despite recent reports from much smaller epidemiologic studies or laboratory animals, these results provide reassurance that antidepressant use is not associated with the development of breast cancer.

Adult↗
PubMed2001

Unhealthy ageing: functional and socioeconomic impact.

The long-term impacts of disease on functional status and on cost loom larger in the elderly than in any other age group. In older patients, the chronic sequelae of myocardial infarction and stroke often account for greater functional disability and resource utilization than does the initial acute presentation. In order to study this, quantitative measures from clinical and functional status assessments must be related to lifelong resource use. Rigorous measurement of such outcomes can render it possible to measure the impact on the health care system of specific cardiovascular and cerebrovascular consequences of 'unhealthy ageing'. If performed in the context of a randomized clinical trial studying the effect of preventive measures, this approach can also lay the groundwork for assessment of the clinical and economic benefits of measures taken to reduce such morbidity.

Aged↗
PubMed2001

Finding incident breast cancer cases through US claims data and a state cancer registry.

OBJECTIVE: With the increasing availability of automated health-care data, new methods are available to screen large populations for the presence of cancer diagnoses. However, it is crucial to evaluate how completely incident cancer cases can be ascertained using these data sources. METHODS: We used capture-recapture techniques to estimate the total number of incident breast cancer cases occurring within one state during a 3-year period. We then compared the ascertainment of these cases by the following two data sources: claims for breast cancer surgery recorded in Medicaid and Medicare data vs a cancer registry in the same state. RESULTS: Medicaid-Medicare breast cancer surgery claims identified 68% of the total estimated number of incident breast cancer cases while cancer registry data identified 78%. Case ascertainment improved markedly to 91% when both registry and Medicare-Medicaid data sources were used together. The sensitivity of ascertainment was lower for Medicaid-Medicare data among those aged under 65 and non-white; ascertainment was lower for the registry among women who were aged under 65, poor, and non-white. CONCLUSIONS: Combining health insurance claims data with a population-based cancer registry improved the identification of incident cases of breast cancer, and may be particularly useful among demographic groups found to be at highest risk of under-ascertainment such as younger women, the poor, and racial minorities.

Adult↗
PubMed2001

Late referral and modality choice in end-stage renal disease.

BACKGROUND: We sought to determine whether late versus early referral to a nephrologist in patients with chronic kidney disease influences the initial choice of hemodialysis (HD) versus peritoneal dialysis (PD) or the likelihood of switching treatment modalities in the first six months of therapy. METHODS: Using New Jersey Medicare/Medicaid claims, all patients who started RRT between January 1991 and June 1996 and were diagnosed with renal disease more than one year prior to RRT were identified. In the resulting cohort of 3014 patients, 35% had their first nephrologist consultation < or =90 days prior to initiation of dialysis. RESULTS: After controlling for demographic characteristics, socioeconomic status and underlying renal disease, age, black race [Odds ratio (OR) = 0.56], race other than black or white (OR = 0.56), and socioeconomic status (OR = 0.68) influenced the choice of initial treatment modality, but timing of the referral did not. However, patients starting on PD who were referred late were 50% more likely to switch to HD than were patients who saw a nephrologist earlier [Hazard's ratio (HR) = 1.47]. In patients originally on HD, diabetic nephropathy (HR = 1.49) and black race (HR = 0.69) influenced the likelihood of switching to PD, but the timing of referral did not. CONCLUSIONS: These results refute earlier findings that late referral may limit access to PD. We found that modality choice depends on factors such as age, race, or socioeconomic status, rather than on than timing of nephrologist referral. Late referral does not influence the likelihood to switch modality in patients starting on HD, but does so in patients starting on PD.

Adult↗
PubMed2001

Determinants of delayed nephrologist referral in patients with chronic kidney disease.

Late referral to nephrologists of patients with chronic kidney disease (CKD) is a major public health problem because it is prevalent and associated with increased morbidity, mortality, and greater healthcare costs. To identify factors associated with delayed nephrologist referral (first nephrologist visit < 90 days before the onset of renal replacement therapy), we identified a cohort of patients with preexisting CKD that progressed to end-stage renal failure. We developed a logistic regression model to measure the association of specific demographic and clinical covariates with delayed nephrologist referral. Delayed referral was highly associated with older age (P < 0.001), race other than white or black (P = 0.002), and the absence of certain comorbidities: hypertension (P < 0.001), coronary artery disease (P < 0.001), malignancy (P = 0.005), and diabetes (P = 0.02). Associations of late referral with male sex (P = 0.07) and lower socioeconomic status (P = 0.09) were of borderline significance. Patients who were predominantly cared for by a general internist were more likely to be referred late to a nephrologist compared with those cared for by a family or primary care practitioner (P = 0.002) or another subspecialist (P = 0.019). These findings suggest that several factors increase the risk that patients with CKD will have the first nephrologist consultation excessively late in the course of their disease. Although timely access to nephrologist services is important for all patients with advanced CKD, this is of particular concern in older patients, those in certain minority populations, and those in whom the absence of comorbidity may provide a false sense of true risk status.

Age Distribution↗