Effect of BMI and fat mass on HIV disease progression in HIV-infected, antiretroviral treatment-naïve adults in Botswana.

An obesity paradox has been proposed in many conditions including HIV. Studies conducted to investigate obesity and its effect on HIV disease progression have been inconclusive and are lacking for African settings. This study investigated the relationship between overweight/obesity (BMI≥25 kg/m2) and HIV disease progression in HIV+ asymptomatic adults not on antiretroviral treatment (ART) in Botswana over 18 months. A cohort study in asymptomatic, ART-naïve, HIV+ adults included 217 participants, 139 with BMI of 18·0-24·9 kg/m2 and seventy-eight participants with BMI≥25 kg/m2. The primary outcome was time to event (≥25 % decrease in cluster of differentiation 4 (CD4) cell count) during 18 months of follow-up; secondary outcomes were time to event of CD4 cell count<250 cells/µl and AIDS-defining conditions. Proportional survival hazard models were used to compare hazard ratios (HR) on time to events of HIV disease progression over 18 months. Higher baseline BMI was associated with significantly lower risk of an AIDS-defining condition during the follow-up (HR 0·218; 95 % CI 0·068, 0·701; P=0·011). Higher fat mass at baseline was also significantly associated with decreased risk of AIDS-defining conditions during the follow-up (HR 0·855; 95 % CI 0·741, 0·987; P=0·033) and the combined outcome of having CD4 cell count≤250/µl and AIDS-defining conditions, whichever occurred earlier (HR 0·918; 95 % CI 0·847, 0·994; P=0·036). All models were adjusted for covariates. Higher BMI and fat mass among the HIV-infected, ART-naïve participants were associated with slower disease progression. Mechanistic research is needed to evaluate the association between BMI, fat mass and HIV disease progression.

Framingham score and LV mass predict events in young adults: CARDIA study.

BACKGROUND: Framingham risk score (FRS) underestimates risk in young adults. Left ventricular mass (LVM) relates to cardiovascular disease (CVD), with unclear value in youth. In a young biracial cohort, we investigate how FRS predicts CVD over 20 years and the incremental value of LVM. We also explore the predictive ability of different cut-points for hypertrophy. METHODS: We assessed FRS and echocardiography-derived LVM (indexed by body surface area or height2.7) from 3980 African-American and white Coronary Artery Risk Development in Young Adults (CARDIA) participants (1990-1991); and followed over 20 years for a combined endpoint: cardiovascular death; nonfatal myocardial infarction, heart failure, cerebrovascular disease, and peripheral artery disease. We assessed the predictive ability of FRS for CVD and also calibration, discrimination, and net reclassification improvement for adding LVM to FRS. RESULTS: Mean age was 30±4 years, 46% males, and 52% white. Event incidence (n=118) across FRS groups was, respectively, 1.3%, 5.4%, and 23.1% (p<0.001); and was 1.4%, 1.3%, 3.7%, and 5.4% (p<0.001) across quartiles of LVM (cut-points 117 g, 144 g, and 176 g). LVM predicted CVD independently of FRS, with the best performance in normal weight participants. Adding LVM to FRS modestly increased discrimination and had a statistically significant reclassification. The 85th percentile (≥116 g/m2 for men; ≥96 g/m2 for women) showed event prediction more robust than currently recommended cut-points for hypertrophy. CONCLUSION: In a biracial cohort of young adults, FRS and LVM are helpful independent predictors of CVD. LVM can modestly improve discrimination and reclassify participants beyond FRS. Currently recommended cut-points for hypertrophy may be too high for young adults.

Prospective association of serum androgens and sex hormone-binding globulin with subclinical cardiovascular disease in young adult women: the "Coronary Artery Risk Development in Young Adults" women's study.

CONTEXT: The role of endogenous androgens and SHBG in the development of cardiovascular disease in young adult women is unclear. OBJECTIVE: Our objective was to study the prospective association of serum androgens and SHBG with subclinical coronary and carotid disease among young to middle-aged women. DESIGN AND SETTING: This was an ancillary study to the Coronary Artery Risk Development in Young Adults (CARDIA) study, a population-based multicenter cohort study with 20 yr of follow-up. PARTICIPANTS: Participants included 1629 women with measurements of serum testosterone and SHBG from yr 2, 10, or 16 and subclinical disease assessment at yr 20 (ages 37-52 yr). MAIN OUTCOME MEASURES: Coronary artery calcified plaques (CAC) and carotid artery intima-media thickness (IMT) were assessed at yr 20. The IMT measure incorporated the common carotid arteries, bifurcations, and internal carotid arteries. RESULTS: SHBG (mean of yr 2, 10, and 16) was inversely associated with the presence of CAC (multivariable adjusted odds ratio for women with SHBG levels above the median = 0.59; 95% confidence interval = 0.40-0.87; P = 0.008). SHBG was also inversely associated with the highest quartile of carotid-IMT (odds ratio for women with SHBG levels in the highest quartile = 0.56; 95% confidence interval = 0.37-0.84; P for linear trend across quartiles = 0.005). No associations were observed for total or free testosterone with either CAC or IMT. CONCLUSION: SHBG levels were inversely associated with subclinical cardiovascular disease in young to middle-aged women. The extent to which low SHBG is a risk marker or has its own independent effects on atherosclerosis is yet to be determined.

Reasons for placement of restorations on previously unrestored tooth surfaces by dentists in The Dental Practice-Based Research Network.

OBJECTIVE: The authors conducted a study to identify and quantify the reasons used by dentists in The Dental Practice-Based Research Network (DPBRN) for placing restorations on unrestored permanent tooth surfaces and the dental materials they used in doing so. METHODS: A total of 229 DPBRN practitioner-investigators provided data from their practices regarding 9,890 consecutive restorations in 5,810 patients. Information the practitioner-investigators provided included their reasons for restoring the teeth, the specific teeth and surfaces they restored and the restorative materials they used. RESULTS: Primary caries (85 percent of teeth, 8,351 of 9,890) and noncarious defects (15 percent, 1,479 of 9,890) were the main reasons participants gave for placing restorations. Participants placed restorations necessitated by caries most frequently on occlusal surfaces (49 percent, 4,091 of 8,351). They used amalgam for 47 percent of the molar restorations and 45 percent of the premolar restorations. They used directly placed resin-based composite (RBC) for 48 percent of the molar restorations, 50 percent of the premolar restorations and 93 percent of the anterior restorations. CONCLUSION: DPBRN practitioner-investigators cited dental caries on occlusal and proximal surfaces of molar teeth as the main reasons for placing restorations on previously unrestored tooth surfaces. RBC was the material they used most commonly for occlusal and anterior restorations. Amalgam remains the material of choice to restore posterior teeth with proximal caries, although the authors noted significant differences in the use of amalgam and RBC by dentists in various regions of the DPBRN.

Association between patterns of nucleotide variation across the three fibrinogen genes and plasma fibrinogen levels: the Coronary Artery Risk Development in Young Adults (CARDIA) study.

BACKGROUND: Previous genotype-phenotype association studies of fibrinogen have been limited by incomplete knowledge of genomic sequence variation within and between major ethnic groups in FGB, FGA, and FGG. METHODS: We characterized the linkage disequilibrium patterns and haplotype structure across the human fibrinogen gene locus in European- and African-American populations. We analyzed the association between common polymorphisms in the fibrinogen genes and circulating levels of both 'functional' fibrinogen (measured by the Clauss clotting rate method) and total fibrinogen (measured by immunonephelometry) in a large, multi-center, bi-racial cohort of young US adults. RESULTS: A common haplotype tagged by the A minor allele of the well-studied FGB-455 G/A promoter polymorphism (FGB 1437) was confirmed to be strongly associated with increased plasma fibrinogen levels. Two non-coding variants specific to African-American chromosomes, FGA 3845 A and FGG 5729 G, were each associated with lower plasma fibrinogen levels. In European-Americans, a common haplotype tagged by FGA Thr312Ala and several other variant alleles across the fibrinogen gene locus was strongly associated with decreased fibrinogen levels as measured by functional assay, but not by immunoassay. Overall, common polymorphisms within the three fibrinogen genes explain < 2% of the variability in plasma fibrinogen concentration. CONCLUSIONS: In young adults, fibrinogen multi-locus genotypes are associated with plasma fibrinogen levels. The specific single nucleotide polymorphism and haplotype patterns for these associations differ according to population and also according to phenotypic assay. It is likely that a substantial proportion of the heritable component of plasma fibrinogen concentration is due to genetic variation outside the three fibrinogen genes.

Community empowerment--a successful model for prevention of non-communicable diseases in India--the Chennai Urban Population Study (CUPS-17).

BACKGROUND AND OBJECTIVE: Randomized clinical trials have documented that lifestyle changes through physical activity can prevent diabetes. However there is no data whether such strategies are applicable at community level, that is, in a real life setting. This study demonstrates the first attempt in India, to our knowledge, of increasing physical activity through community empowerment in an attempt at primary prevention of non communicable diseases. METHODS: The Chennai Urban Population Study [CUPS] was conducted in the year 1996 in two residential areas: a middle income group the Asiad colony at Tirumangalam, and a low income group at Bharathi Nagar in T. Nagar. The Asiad colony was selected for this study. Of the 524 eligible individuals available at baseline in 1998 [age > or =20 years], 479 individuals consented for the study (response rate: 91.4%). After seven years, in 2004, the number of eligible individuals increased to 712 of whom 705 consented for the study (response rate:99%). Education regarding the benefits of physical activity was provided by mass awareness programmes like public lectures and video clippings. Both at baseline and during follow-up, details about the physical activity were collected using a validated questionnaire, which included job related and leisure time activities, and specific questions on exercise. Study individuals were then graded as having light, moderate and heavy physical activity using a scoring system. RESULTS: In response to the awareness programmes given by our research team, the colony residents constructed a unique public park with their own funds. Though the occupation grades did not change, there was a significant change in the pattern of physical activity. At baseline, only 14.2% of the residents did some form of exercise. more than three times a week, which presently increased to 58.7% [p < 0.001]. The number of subjects who walked more than three times a week increased from 13.8% at baseline to 52.1% during follow-up [p < 0.001]. CONCLUSION: This study is a demonstration of how community empowerment with increased physical activity could possibly lead to prevention of diabetes and other non communicable diseases at the community level. This study also highlights the importance of sharing the results of research studies with the community.

Patterns of lung function in asymptomatic nonsmoking men and women in the People's Republic of China.

PURPOSE: To evaluate patterns of lung function in healthy, working Chinese men and women in different geographic areas of the People's Republic of China (PRC). METHODS: We conducted lung function tests on 2926 asymptomatic, never smoking Chinese men and women aged 35-56 years residing in or around Beijing and Guangzhou. Within each of these locations, separate urban and rural samples were recruited. RESULTS: Age and height adjusted lung function was greater in Beijing than in Guangzhou, and within each city for residents of rural vs. urban areas. Among women, estimated rates of lung aging were greater in Beijing than in Guangzhou, and in urban vs. rural areas. Both FEV(1) and FVC exhibited a curvilinear association with body mass index. CONCLUSIONS: Lung function data from this largely working cohort exhibited marked geographic and urban-rural differences in this never smoking, adult Chinese cohort. Such variation is not uncommon and may reflect differences in body size, diet, and environmental and occupational exposures across these different settings. Caution should be used in applying published reference equations to populations from different parts of the PRC.

Asthma is associated with weight gain in females but not males, independent of physical activity.

We tested whether asthma diagnosis is associated with weight gain and physical activity in 4,547 18 to 30-yr-old African American and white men and women, followed prospectively for up to 10 yr. Baseline asthma was most frequent in African American men. Incident asthma was more frequent in women. Incident asthma was associated with highest and lowest baseline and change in body mass index (BMI), in a J-shaped curve, after adjustment for other factors. When stratified by sex, this association was seen only in females. Subjects on average decreased physical activity and gained weight over time, but there was no significant difference in asthma prevalence by physical activity at baseline or asthma incidence by change in physical activity. Cigarette smoking in females was significantly associated with asthma incidence, but serum cotinine level at baseline among nonsmokers (reflecting environmental tobacco smoke [ETS] exposure) was not significantly associated with asthma. We conclude that gain in BMI predisposes to new asthma diagnosis in female young adults, but decreased physical activity does not explain the association of weight gain with asthma.

Improving quality improvement using achievable benchmarks for physician feedback: a randomized controlled trial.

CONTEXT: Performance feedback and benchmarking, common tools for health care improvement, are rarely studied in randomized trials. Achievable Benchmarks of Care (ABCs) are standards of excellence attained by top performers in a peer group and are easily and reproducibly calculated from existing performance data. OBJECTIVE: To evaluate the effectiveness of using achievable benchmarks to enhance typical physician performance feedback and improve care. DESIGN: Group-randomized controlled trial conducted in December 1996, with follow-up through 1998. SETTING AND PARTICIPANTS: Seventy community physicians and 2978 fee-for-service Medicare patients with diabetes mellitus who were part of the Ambulatory Care Quality Improvement Project in Alabama. INTERVENTION: Physicians were randomly assigned to receive a multimodal improvement intervention, including chart review and physician-specific feedback (comparison group; n = 35) or an identical intervention plus achievable benchmark feedback (experimental group; n = 35). MAIN OUTCOME MEASURE: Preintervention (1994-1995) to postintervention (1997-1998) changes in the proportion of patients receiving influenza vaccination; foot examination; and each of 3 blood tests measuring glucose control, cholesterol level, and triglyceride level, compared between the 2 groups. RESULTS: The proportion of patients who received influenza vaccine improved from 40% to 58% in the experimental group (P<.001) vs from 40% to 46% in the comparison group (P =.02). Odds ratios (ORs) for patients of achievable benchmark physicians vs comparison physicians who received appropriate care after the intervention, adjusted for preintervention care and nesting of patients within physicians, were 1.57 (95% confidence interval [CI], 1.26-1.96) for influenza vaccination, 1.33 (95% CI, 1.05-1.69) for foot examination, and 1.33 (95% CI, 1.04-1.69) for long-term glucose control measurement. For serum cholesterol and triglycerides, the achievable benchmark effect was statistically significant only after additional adjustment for physician characteristics (OR, 1.40 [95% CI, 1.08-1.82] and OR, 1.40 [95% CI, 1.09-1.79], respectively). CONCLUSION: Use of achievable benchmarks significantly enhances the effectiveness of physician performance feedback in the setting of a multimodal quality improvement intervention.

Ten-year changes in smoking among young adults: are racial differences explained by socioeconomic factors in the CARDIA study?

OBJECTIVES: This study investigated whether socioeconomic factors explain racial/ethnic differences in regular smoking initiation and cessation. METHODS: Data were derived from the CARDIA study, a cohort of 5115 healthy adults aged 18 to 30 years at baseline (1985-1986) and recruited from the populations of 4 US cities. Respondents were followed over 10 years. RESULTS: Among 3950 respondents reexamined in 1995-1996, 20% of Whites and 33% of African Americans were smokers, as compared with 25% and 32%, respectively, in 1985-1986. On average, African Americans were of lower socioeconomic status. Ten-year regular smoking initiation rates for African American women, White women, African American men, and White men were 7.1%, 3.5%, 13.2%, and 5.1%, respectively, and the corresponding cessation rates were 25%, 35.1%, 19.2%, and 31.3%. After adjustment for socioeconomic factors, most 95% confidence intervals of the odds ratios for regular smoking initiation and cessation in African Americans vs Whites included 1. CONCLUSIONS: Less beneficial 10-year changes in smoking were observed in African Americans, but socioeconomic factors explained most of the racial disparity.

Changes in US health care access in the 90s: race and income differences from the CARDIA Study. Coronary Artery Risk Development in Young Adults.

OBJECTIVE: Health care financing is changing rapidly in the United States. We investigated whether and how health care access is changing concurrently with changes in financing, with special attention to a minority population. METHODS: We examined a longitudinal biracial (half African-American, half White) urban cohort of 3,565 individuals, aged 25-37 years old, in 1992-93 and again in 1995-96. We measured access by self-reported (1) health insurance status, (2) regular source of medical care, and (3) lack of care due to financial problems. RESULTS: In 1992-93, 30.3% of the cohort experienced at least one access barrier, with a decline to 26.8% in 1995-96 (P<.005). However, access improved more for Whites than for African Americans; and access improved for higher, but not for lower, income groups (7% improvement for high income, vs 2% deterioration for lower income, P<.01). In addition, there was an 11% to 19% absolute increase in individuals making co-payments for health care utilization across all race/sex groups, with African Americans having markedly higher proportions of cost-sharing. African-American, low income, and unemployed individuals reported more acute care, but fewer outpatient visits. Income and employment explained racial differences. CONCLUSION: While access has improved or stabilized for higher income groups, there is a widening gap according to income, accompanied by an acute care pattern for low income groups that may be both inadequate and cost inefficient.

Relationship of hospital teaching status with quality of care and mortality for Medicare patients with acute MI.

CONTEXT: Issues of cost and quality are gaining importance in the delivery of medical care, and whether quality of care is better in teaching vs nonteaching hospitals is an essential question in this current national debate. OBJECTIVE: To examine the association of hospital teaching status with quality of care and mortality for fee-for-service Medicare patients with acute myocardial infarction (AMI). DESIGN, SETTING, AND PATIENTS: Analysis of Cooperative Cardiovascular Project data for 114,411 Medicare patients from 4361 hospitals (22,354 patients from 439 major teaching hospitals, 22,493 patients from 455 minor teaching hospitals, and 69,564 patients from 3467 nonteaching hospitals) who had AMI between February 1994 and July 1995. MAIN OUTCOME MEASURES: Administration of reperfusion therapy on admission, aspirin during hospitalization, and beta-blockers and angiotensin-converting enzyme inhibitors at discharge for patients meeting strict inclusion criteria; mortality at 30, 60, and 90 days and 2 years after admission. RESULTS: Among major teaching, minor teaching, and nonteaching hospitals, respectively, administration rates for aspirin were 91.2%, 86.4%, and 81.4% (P<.001); for angiotensin-converting enzyme inhibitors, 63. 7%, 60.0%, and 58.0% (P<.001); for beta-blockers, 48.8%, 40.3%, and 36.4% (P<.001); and for reperfusion therapy, 55.5%, 58.9%, and 55.2% (P =.29). Differences in unadjusted 30-day, 60-day, 90-day, and 2-year mortality among hospitals were significant at P<.001 for all time periods, with a gradient of increasing mortality from major teaching to minor teaching to nonteaching hospitals. Mortality differences were attenuated by adjustment for patient characteristics and were almost eliminated by additional adjustment for receipt of therapy. CONCLUSIONS: In this study of elderly patients with AMI, admission to a teaching hospital was associated with better quality of care based on 3 of 4 quality indicators and lower mortality. JAMA. 2000;284:1256-1262

Incidence and correlates of hypertension in the Atherosclerosis Risk in Communities (ARIC) study and the Monitoring Trends and Determinants of Cardiovascular Disease (POL-MONICA) project.

OBJECTIVE: The purpose of this research is to assess short-term blood pressure change and hypertension incidence, and identify correlates of incident hypertension in the USA and Poland. DESIGN AND METHODS: Population-based samples aged 45-64 years at enrollment from the Atherosclerosis Risk in Communities (ARIC) and the Pol-MONICA studies: including 3777 whites from Minneapolis, Minnesota, USA suburbs (urban), 3635 whites from Washington County, Maryland, USA (semi-rural) and 3109 blacks from Jackson, Mississippi, USA surveyed in 1987-1989 and 1990-1992; and 389 persons from Warsaw, Poland (urban) and 322 from Tarnobrzeg Province, Poland (semi-rural) surveyed in 1987-1988 and 1992-1993. RESULTS: Age-standardized systolic and diastolic blood pressures at both screens were 9-20 and 5-9 mmHg higher in the Polish samples than in US blacks, who had higher levels than US whites. Age-adjusted annual hypertension incidence in both Polish male cohorts (6-8%) was higher than that in US white men (4%) and approaching that of US black men (7%); rates were also higher in Polish female cohorts (8-9%) than in US black women (8%), but nearly twice those in US white women (4%). Factors independently related to hypertension incidence included age, family history, smoking, baseline blood pressures and body mass index, and increase in body mass index and alcohol consumption between screenings. After adjustment for these factors, annualized hypertension incidence was similar in US white and Polish men (2.3 and 2.7%) compared with US black men (3.4%), and in US white and Polish women (1.5 and 1.3%) compared with US black women (3.9%). CONCLUSIONS: Despite substantial differences in blood pressure levels and age-standardized hypertension incidence rates, the differences in incidence between Polish and US white men appear to be explained largely by differences in risk factors for hypertension.

Weight gain continues in the 1990s: 10-year trends in weight and overweight from the CARDIA study. Coronary Artery Risk Development in Young Adults.

The prevalence of obesity increased in the United States through the 1980s. The authors examined 10-year aging and secular (time-related) trends in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort for indications of whether these trends are continuing and for ages of peak weight gain in young adults. CARDIA is a population-based, prospective study of 5,115 African-American and White men and women aged 18-30 years at baseline. Body weight and overweight prevalence were measured at five time points from 1985-1986 to 1995-1996. Linear, mixed-model regression was used to partition weight gain into that due to secular trends and that due to aging. Prevalence of overweight (body mass index (BMI) > or = 25.0 kg/m2) increased markedly, and prevalence of severe obesity (BMI > or = 40.0 kg/m2) doubled in all race-sex groups. Each race-sex group experienced significant secular weight gains, ranging from 0.96 kg/year (95% confidence interval: 79, 1.13) in African-American women to 0.55 kg/year (95% confidence interval: 0.41, 0.69) in White women. Significant secular gains were present during each follow-up period. Each race-sex group also experienced significant weight increases related to aging during their early to midtwenties. Secular trends for weight gain are continuing in CARDIA, but the magnitude of weight gain differed among the four race-sex groups.

Comparison of electrocardiographic findings between Northern and Southern Chinese population samples.

BACKGROUND: Cardiovascular disease is rare in China, but there are few data on the prevalence of electrocardiographic (ECG) abnormalities in Chinese populations. METHODS: The ECG surveys were carried out in four Chinese population samples, in a total of 9,666 adults aged 35-54 in Beijing and Guangzhou, China from 1981 to 1984. Twelve-lead resting ECG tracings were coded by the Minnesota Code. RESULTS: Prevalence per 1,000 of abnormal ECG ranged from 77.4 to 209.8, and was higher for men than women and higher for Guangzhou than Beijing. Prevalence per 1,000 of major abnormalities in Guangzhou was 29.8 for men and 78.4 for women, higher than the 18.4 and 29.6 for counterparts in Beijing. The ECG changes attributed in 'Western' populations to coronary heart disease (CHD), such as large Q waves (Minnesota Code 1-1, 1-2) and ST-T abnormalities, were similar between Beijing and Guangzhou men, but Guangzhou women had much higher prevalence of ST-T abnormalities than Beijing women. Other ECG abnormalities such as A-V block, left branch bundle block, and left ventricular hypertrophy were rare in people of both sites. CONCLUSIONS: Compared with similar data from the US, these Chinese populations had a relatively low prevalence of ECG abnormalities putatively related to CHD. This corresponds with the low incidence of CHD in the Chinese population. However, within the Chinese populations of this study, a high abnormality rate appeared in a population with low incidence of CHD and hypertension (Guangzhou women). Reasons why ECG abnormalities do not parallel prevalence levels of CHD and hypertension remain to be elucidated.

Weight gain and its correlates in Poland between 1983 and 1993.

BACKGROUND: Weight gain and its unfavorable consequences on coronary heart disease (CHD) risk have been observed worldwide. Determinants of weight gain were studied in a Polish cohort of 1042 men and women age 35-64 at baseline. Participants were randomly selected from an urban population in Warsaw and a rural population in Tarnobrzeg Province surveyed by investigators in Krakow. The surveys, part of the Pol-MONICA project, were conducted in 1983-1984, 1987-1988, and 1992-1993. The purpose of this report is to gain insight into the dynamics of weight gain in this population that could be helpful in identifying high-risk groups for intervention, and to determine if economic changes that took place shortly after the second survey had any impact on weight gain. METHODS: Weight, height and demographic characteristics were measured at each visit according to Pol-MONICA standard protocol. Body mass index (BMI) was calculated as kg/m2. Years of schooling, 7-day alcohol history and smoking history were self-reported. RESULTS: Sixty percent of the cohort gained some weight, averaging 0.3-0.7kg/y. Weight gain was highest in younger rural women, in urban men and in rural women with low education. In multiple linear regression, low education was related to a 1.29 kg greater weight gain (P<0.01), ex-smoking status was related to a 2.54 kg greater weight gain (P<0.001), and younger age was related to a 1.14 kg greater weight gain (P<0.001). CONCLUSION: Our results indicate a need to target intervention programs at young low SES adults. Developing effective means of reaching these vulnerable groups is a critical research goal.

Comparison of outcomes research with clinical trials using preexisting data.

Outcomes research using analysis of preexisting data is a relatively new field with the potential to improve the quality and effectiveness of medical care, and may provide a useful complement to randomized studies. Motivated by the growth of this research in the cardiovascular literature, this review offers a framework to identify the core concepts of outcomes research from database analyses by comparing and contrasting it with the randomized clinical trial.

Achievable benchmarks of care: the ABCs of benchmarking.

Benchmarking is generally considered to be an important tool for quality improvement. Traditional approaches to benchmarking have relied on subjective identification of 'leaders in the field'. We derive an objective, reproducible and attainable Achievable Benchmark of Care (ABC) by measuring and analysing performance on process-of-care indicators. Three characteristics of the ABC that we deem essential are: (1) benchmarks represent a measurable level of excellence; (2) benchmarks are demonstrably attainable; (3) benchmarks are derived from data in an objective, reproducible and predetermined fashion. From these characteristics it follows that (4) providers with high performance are selected to define a level of excellence in a predetermined fashion, but (5) providers with high performance on small numbers of cases do not influence unduly benchmark levels. We use the 'pared mean' to operationalize the ABC. Roughly, the pared mean summarizes the performance of top-ranked providers whereby at least 10% of the patient pool across all providers is included. Bayesian estimators for adjustment of performance of providers with small sample sizes are used to rank providers. Randomized controlled trials to assess the independent effect of the ABC in quality improvement projects are under way. We have developed a methodology objectively and reproducibly to derive a level of excellent, attainable performance, based on measured performance by a group of providers. The ABC can be applied to groups of providers in communities, to institutions and departments within them, or to individual practitioners.