The Effect of Chronic Kidney Disease on a Physical Activity Intervention: Impact on Physical Function, Adherence, and Safety

Background

Because chronic kidney disease (CKD) is associated with muscle wasting, older adults with CKD are likely to have physical function deficits. Physical activity can improve these deficits, but whether CKD attenuates the benefits is unknown. Our objective was to determine if CKD modified the effect of a physical activity intervention in older adults.

Methods

This is an exploratory analysis of the LIFE-P study, which compared a 12-month physical activity program (PA) to a successful aging education program (SA) in older adults. CKD was defined as a baseline eGFR < 60 mL/min/1.73 m². We examined the Short Physical Performance Battery (SPPB) at baseline, 6 and 12 months. Secondary outcomes included serious adverse events (SAE) and adherence to intervention frequency. Linear mixed models were adjusted for age, sex, diabetes, hypertension, CKD, intervention, site, visit, baseline SPPB, and interactions of intervention and visit and of intervention, visit, and baseline CKD.

Results

The sample included 368 participants. CKD was present in 105 (28.5%) participants with a mean eGFR of 49.2 ± 8.1 mL/min/1.73 m². Mean SPPB was 7.38 ± 1.41 in CKD participants; 7.59 ± 1.44 in those without CKD (p = 0.20). For CKD participants in PA, 12-month SPPBs increased to 8.90 (95% CI 8.32, 9.47), while PA participants without CKD increased to 8.40 (95% CI 8.01, 8.79, p = 0.43). For CKD participants in SA, 12-month SPPBs increased to 7.67 (95% CI 7.07, 8.27), while participants without CKD increased to 8.12 (95% CI 7.72, 8.52, p = 0.86). Interaction between CKD and intervention was non-significant (p = 0.88). Number and type of SAEs were not different between CKD and non-CKD participants (all p > 0.05). In PA, adherence for CKD participants was 65.5 ± 25.4%, while for those without CKD was 74.0 ± 22.2% (p = 0.12).

Conclusion

Despite lower adherence, older adults with CKD likely derive clinically meaningful benefits from physical activity with no apparent impact on safety, compared to those without CKD.

Effects of a One-Year Physical Activity Program on Serum C-Terminal Agrin Fragment (CAF) Concentrations among Mobility-Limited Older Adults

OBJECTIVES

C-terminal Agrin Fragment (CAF) has been proposed as a potential circulating biomarker for predicting changes in physical function among older adults. To determine the effect of a one-year PA intervention on changes in CAF concentrations and to evaluate baseline and longitudinal associations between CAF concentrations and indices of physical function.

DESIGN

Ancillary study to the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P), a multi-site randomized clinical trial designed to evaluate the effects of chronic exercise on the physical function of older adults at risk for mobility disability.

SETTING

Four academic research centers within the U.S.

PARTICIPANTS

Three hundred thirty three older adults aged 70 to 89 with mild to moderate impairments in physical function.

INTERVENTION

A 12-month intervention of either structured physical activity (PA) or health education promoting successful aging (SA).

MEASUREMENTS

Serum CAF concentrations and objectives measures of physical function - i.e. gait speed and performance on the Short Physical Performance Battery (SPPB).

RESULTS

The group*time interaction was not significant for serum CAF concentrations (p=0.265), indicating that the PA intervention did not significantly reduce serum CAF levels compared to SA. Baseline gait speed was significantly correlated with baseline CAF level (r = -0.151, p= 0.006), however the association between CAF and SPPB was not significant. Additionally, neither baseline nor the change in CAF concentrations strongly predicted the change in either performance measure following the PA intervention.

CONCLUSION

In summary, the present study shows that a one-year structured PA program did not reduce serum CAF levels among mobility-limited older adults. However, further study is needed to definitively determine the utility of CAF as a biomarker of physical function.

Association of age and packed red blood cell transfusion to 1-year survival--an observational study of ICU patients

OBJECTIVES

To compare the 1-year survival for different age strata of intensive care unit (ICU) patients after receipt of packed red blood cell (PRBC) transfusions.

BACKGROUND

Despite guidelines documenting risks of PRBC transfusion and data showing that increasing age is associated with ICU mortality, little data exist on whether age alters the transfusion-related risk of decreased survival.

METHODS

We retrospectively examined data on 2393 consecutive male ICU patients admitted to a tertiary-care hospital from 2003 to 2009 in age strata: 21-50, 51-60, 61-70, 71-80 and >80 years. We calculated Cox regression models to determine the modifying effect of age on the impact of PRBC transfusion on 1-year survival by using interaction terms between receipt of transfusion and age strata, controlling for type of admission and Charlson co-morbidity indices. We also examined the distribution of admission haematocrit and whether transfusion rates differed by age strata.

RESULTS

All age strata experienced statistically similar risks of decreased 1-year survival after receipt of PRBC transfusions. However, patients age >80 were more likely than younger cohorts to have haematocrits of 25-30% at admission and were transfused at approximately twice the rate of each of the younger age strata.

DISCUSSION

We found no significant interaction between receipt of red cell transfusion and age, as variables, and survival at 1 year as an outcome.

Practical Research Strategies for Reducing Social and Racial/Ethnic Disparities in Obesity

Adult and childhood obesity and related adverse outcomes are most common among racial/ethnic minorities and socio-economically disadvantaged populations in the United States . Research approaches to obesity developed in mainstream populations and deploying new information technologies may exacerbate existing disparities in obesity. Current obesity management and prevention research priorities will not maximally impact this critical problem unless investigators explicitly focus on discovering innovative strategies for preventing and managing obesity in the disadvantaged populations that are most affected. On the basis of our research experience, four key research approaches are needed: (1) elucidating the underlying social forces that lead to disparities; (2) directly involving community members in the development of research questions and research methods; (3) developing flexible strategies that allow tailoring to multiple disadvantaged populations; and (4) building culturally and socio-economically tailored strategies specifically for populations most affected by obesity. Our experience with a community-based longitudinal cohort study and two health center-based clinical trials illustrate these principles as a contrast to traditional research priorities that can inadvertently worsen existing social inequities. If obesity research does not directly address healthcare and health-outcome disparities, it will contribute to their perpetuation.

Underdiagnosis of hypertension using electronic health records

BACKGROUND

Hypertension is highly prevalent and contributes to cardiovascular morbidity and mortality. Appropriate identification of hypertension is fundamental for its management. The rates of appropriate hypertension diagnosis in outpatient settings using an electronic health record (EHR) have not been well studied. We sought to identify prevalent and incident hypertension cases in a large outpatient healthcare system, examine the diagnosis rates of prevalent and incident hypertension, and identify clinical and demographic factors associated with appropriate hypertension diagnosis.

METHODS

We analyzed a 3-year, cross-sectional sample of 251,590 patients aged ≥18 years using patient EHRs. Underlying hypertension was defined as two or more abnormal blood pressure (ABP) readings ≥140/90 mm Hg and/or pharmaceutical treatment. Appropriate hypertension diagnosis was defined by the reporting of ICD-9 codes (401.0-401.9). Factors associated with hypertension diagnosis were assessed through multivariate analyses of patient clinical and demographic characteristics.

RESULTS

The prevalence of hypertension was 28.7%, and the diagnosis rate was 62.9%. The incidence of hypertension was 13.3%, with a diagnosis rate of 19.9%. Predictors of diagnosis for prevalent hypertension included older age, Asian, African American, higher body mass index (BMI), and increased number of ABP readings. Predictors for incident hypertension diagnosis were similar. In patients with two or more ABP readings, hypertension diagnosis was associated with significantly higher medication treatment rates (92.6% vs. 15.8%, P < 0.0001).

CONCLUSIONS

Outpatient EHR diagnosis rates are suboptimal, yet EHR diagnosis of hypertension is strongly associated with treatment. Targeted efforts to improve diagnosis should be a priority.

A trial of inpatient indication based prescribing during computerized order entry with medications commonly used off-label

BACKGROUND

Requiring indications for inpatient medication orders may improve the quality of prescribing and allow for easier placement of diagnoses on the problem list. Indications for inpatient medication orders are also required by some regulators.

OBJECTIVE

This study assessed a clinical decision support (CDS) system designed to obtain indications and document problems during inpatient computerized physician order entry (CPOE) of medications frequently used off-label.

METHODS

A convenience sample of three medications frequently used off-label were selected: the PPI lansoprazole; intravenous immune globulin, and recombinant Factor VIIa. Alerts triggered when a medication was ordered without an FDA approved indication in the problem list. The alerts prompted clinicians to enter either a labeled or off-label indication for the order. Chart review was used as the gold standard to assess the accuracy of clinician entered information.

RESULTS

The PPI intervention generated 873 alerts during 60 days of operation; IVIG 55 alerts during alerts during 93 days; Factor VIIa 25 alerts during 175 days. Agreement between indications entered and chart review was 63% for PPI, 49% for IVIG, and 29% for Factor VIIa. The alerts for PPI, IVIG and Factor VIIa alerts produced accurate diagnoses for the problem list 9%, 16% and 24% respectively. Rates of off-label use measured by chart review were 87% for PPI, and 100% for IVIG and factor VIIa, which were higher than if measured using the ordering clinicians' indications.

CONCLUSION

This trial of indication-based prescribing using CDS and CPOE produced less than optimal accuracy of the indication data as well as a low yield of accurate problems placed on the problem list. These results demonstrate the challenge inherent in obtaining accurate indication information during prescribing and should raise concerns over potential mandates for indication based prescribing and motivate further study of appropriate mechanisms to obtain indications during CPOE.

Increasing off-label use of antipsychotic medications in the United States, 1995-2008

OBJECTIVE

To evaluate patterns of antipsychotic use. DESIGN, SETTING, AND MEASUREMENTS: We used nationally representative data from the IMS Health National Disease and Therapeutic Index to describe outpatient antipsychotic use. The primary outcome was the volume of visits where antipsychotics were used for specific indications (treatment visits). We also quantified use without U.S. Food and Drug Administration approval (off-label use) and off-label use with compendium data suggesting an uncertain evidence base.

RESULTS

Antipsychotic use increased from 6.2 million (M) treatment visits (95% CI, 5.4-7.0) in 1995 to 16.7 M visits (15.5-18.2) in 2006, then declined to 14.3 M visits (13.0-15.6) by 2008. A shift occurred from typical agents in 1995 (84% of all antipsychotic visits) to atypical agents by 2008 (93%). As they declined, typical medications shifted toward use in schizophrenia (30% in 1995 to 48% 2008). In contrast, use of atypical agents expanded for bipolar affective disorder (10 to 34%), remained stable for depression (12 to 14%), and declined for schizophrenia (56 to 23%). Overall, antipsychotic use for indications without FDA approval increased from 4.4 M visits in 1995 to 9.0 M in 2008. The estimated cost associated with off-label use in 2008 was US$6.0 billion.

CONCLUSIONS

Atypical use has grown far beyond substitution for the now infrequently used typical agents. Antipsychotics are increasingly used for conditions where FDA approval and associated clinical evidence is less certain. Despite the value of innovation, the benefits of widening atypical antipsychotic use should be weighed against their cost, regulatory status, and incomplete nature of available evidence.

Variation in routine electrocardiogram use in academic primary care practice

BACKGROUND

Lack of practical consensus regarding routine electrocardiogram (ECG) ordering in primary care led us to hypothesize that nonclinical variations in ordering would exist among primary care providers.

METHODS

We used 2 computerized billing systems to measure ECG ordering at visits to providers in 10 internal medicine group practices affiliated with a large, urban teaching hospital from October 1, 1996, to September 30, 1997. To focus on screening or routine ECGs, patients with known cardiac disease or suggestive symptoms were excluded, as were providers with fewer than 200 annual patient visits. Included were 69 921 patients making 190 238 visits to 125 primary care providers. Adjusted rates of ECG ordering accounted for patient age, sex, and 5 key diagnoses. Logistic regression evaluated additional predictors of ECG ordering.

RESULTS

Electrocardiograms were ordered in 4.4% of visits to patients without reported cardiac disease. Among the 10 group practices, ECG ordering varied from 0.5% to 9.6% of visits (adjusted rates, 0.8%-8.6%). Variations between individual providers were even more dramatic: adjusted rates ranged from 0.0% to 24% of visits, with an interquartile range of 1.4% to 4.7% and a coefficient of variation of 88%. Significant predictors of ECG use were older patient age, male sex, and the presence of clinical comorbidities. Additional nonclinical predictors included Medicare as a payment source, older male providers, and providers who billed for ECG interpretation.

CONCLUSIONS

Variations in ECG ordering are not explained by patient characteristics. The tremendous nonclinical variations in ECG test ordering suggest a need for greater consensus about use of screening ECGs in primary care.

Antibiotic treatment of adults with sore throat by community primary care physicians: a national survey, 1989-1999

CONTEXT

Most sore throats are due to viral upper respiratory tract infections. Group A beta-hemolytic streptococci (GABHS), the only common cause of sore throat warranting antibiotics, is cultured in 5% to 17% of adults with sore throat. The frequency of antibiotic use for pharyngitis has greatly exceeded the prevalence of GABHS, but less is known about specific classes of antibiotics used. Only penicillin and erythromycin are recommended as first-line antibiotics against GABHS.

OBJECTIVES

To measure trends in antibiotic use for adults with sore throat and to determine predictors of antibiotic use and nonrecommended antibiotic use.

DESIGN, SETTING, AND SUBJECTS

Retrospective analysis of 2244 visits to primary care physicians in office-based practices in the National Ambulatory Medical Care Survey, 1989-1999, by adults with a chief complaint of sore throat.

MAIN OUTCOME MEASURES

Treatment with antibiotics and treatment with nonrecommended antibiotics, extrapolated to US annual national rates.

RESULTS

There were an estimated 6.7 million annual visits in the United States by adults with sore throat between 1989 and 1999. Antibiotics were used in 73% (95% confidence interval [CI], 70%-76%) of visits. Patients treated with antibiotics were given nonrecommended antibiotics in 68% (95% CI, 64%-72%) of visits. From 1989 to 1999, there was a significant decrease in use of penicillin and erythromycin and an increase in use of nonrecommended antibiotics, especially extended-spectrum macrolides and extended-spectrum fluoroquinolones (P<.001 for all trends). In multivariable modeling, increasing patient age (odds ratio [OR], 0.86 per decade; 95% CI, 0.79-0.94) and general practice specialty (OR, 1.54 compared with family practice specialty; 95% CI, 1.10-2.14) were independent predictors of antibiotic use. Among patients receiving antibiotics, nonrecommended antibiotic use became more frequent over time (OR, 1.17 per year; 95% CI, 1.11-1.24).

CONCLUSIONS

More than half of adults are treated with antibiotics for sore throat by community primary care physicians. Use of nonrecommended, more expensive, broader-spectrum antibiotics is frequent.

Randomized clinical trials and recent patterns in the use of statins

BACKGROUND

Three landmark trials involving 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) were published between 1994 and 1996 (the Scandinavian Simvastatin Survival Study [4S], the West of Scotland Coronary Prevention Study, and the Cholesterol and Recurrent Events trial). These trials provided evidence that lipid-lowering therapy decreases cardiovascular events, including mortality. Whether these recent data caused a shift toward statin use has not been evaluated.

METHODS

Data from the National Ambulatory Medical Care Survey in 1980, 1981, 1985, and 1989 through 1998 were used. We analyzed 5053 visits by patients taking lipid-lowering medications to office-based physicians selected by stratified random sampling. The main outcome measure was use of specific lipid-lowering medications, including statins.

RESULTS

In 1980 resins and niacin were the most commonly used lipid-lowering medications. By 1985 rising use of fibrates caused reductions in niacin use and resin use. By 1989 statins replaced fibrates as the most heavily used medications. Statin use climbed continuously thereafter, accounting for 90% of visits by patients treated for hypercholesterolemia in 1998. In time series analyses, increases in overall statin use were temporally unrelated to the publication of clinical trials, although the 4S trial may have contributed to a shift from older statins to simvastatin. For patients receiving lipid-lowering therapy in 1993 to 1998, statin use was significantly more likely for female patients, white patients, and patients visiting cardiologists.

CONCLUSIONS

Although the market for lipid-lowering medications is dominated by statins, the rise in statins predated the recent clinical trials supporting their use.

US physicians' treatment of smoking in outpatients with psychiatric diagnoses

A 1996 American Psychiatric Association (APA) guideline recommends the routine treatment of smoking for patients with psychiatric diagnoses. This study evaluates how often US physicians identified and treated smoking among these patients in the ambulatory setting just prior to publication of this guideline, by analysis of 1991-1996 data from the National Ambulatory Medical Care Survey, an annual survey of a random sample of US office-based physicians. Physicians were more likely to identify the smoking status of patients with psychiatric diagnoses compared to patients without these diagnoses (76% vs. 64% of visits, p<0.0001). Smokers with psychiatric diagnoses were more likely to be counseled about smoking than were smokers with non-psychiatric diagnoses (23% vs. 18% of visits, p<0.0001), although the absolute difference was small. Primary care physicians counseled smokers with psychiatric diagnoses more often than did psychiatrists, but both groups of physicians counseled at less than half of smokers' visits. All physicians were more likely to counsel smokers with the diagnosis of anxiety but less likely to counsel smokers with the diagnosis of an affective disorder compared to smokers without these diagnoses. Physicians usually identified the smoking status of patients with psychiatric diagnoses but infrequently acted on this information by counseling smokers to quit. Physicians are missing an important opportunity to prevent tobacco-related morbidity and mortality among this group of patients.

Certain cardiac risk factors predict risk factor interventions and influence communication between physicians and patients

We assessed predictors of cardiac risk factor testing and services and the degree of concordance among patients, physicians, and the medical records for these services, and found considerable variability among different risk factors. The data suggest that baseline risk factors influence communication and performance of interventions and that physicians appear to be underestimating the importance of treating multiple risk factors simultaneously.

National patterns of physician activities related to obesity management

CONTEXT

National physician practices related to the clinical recognition and management of obesity are unknown.

OBJECTIVES

To estimate national patterns of office-based, obesity-related practices and to determine the independent predictors of these practices.

DESIGN

Serial cross-sectional surveys of physician office visits.

SETTING

Ambulatory medical care in the United States.

PATIENTS

We analyzed 55,858 adult physician office visits sampled in the 1995-1996 National Ambulatory Medical Care Surveys. Data from the Third National Health and Nutrition Examination Surveys, 1988-1994 were used to assess and, then, adjust for the underreporting of obesity.

MAIN OUTCOME MEASURES

Reporting of obesity at office visits and physician counseling for weight loss, exercise, and diet among patients identified as obese.

RESULTS

Physicians reported obesity in only 8.6% of 1995-1996 National Ambulatory Medical Care Surveys visits. The 22.7% prevalence rate of the Third National Health and Nutrition Examination Surveys, 1988-1994 suggests that physicians reported obesity in only 38% of their obese patients. Among visits by patients identified as obese, physicians frequently provided counseling for weight loss (35.5%), exercise (32.8%), and diet (41.5%). Adjusted for population prevalence; however, each service was provided to no more than one quarter of all obese patients. While patients with obesity-related comorbidities were treated more aggressively, in these patients, weight loss counseling occurred at only 52% of the visits.

CONCLUSIONS

Specific interventions to address obesity are infrequent in visits to US physicians. Obesity is underreported and interventions are only moderately likely among patients identified as obese, even for those with serious obesity-related comorbidities.

Cardiovascular disease prevention practices by U.S. Physicians for patients with diabetes

OBJECTIVE

Cardiovascular diseases account for the majority of morbidity and mortality in patients with type 2 diabetes mellitus. We describe patterns of cardiovascular disease primary prevention practices used for patients with diabetes by U.S. office-based physicians.

MEASUREMENTS AND MAIN RESULTS

We analyzed a representative sample of 14,038 visits from the 1995 and 1996 National Ambulatory Medical Care Surveys (NAMCS), including 1,489 visits by patients with diabetes. Physicians completed visit forms describing diagnoses, demographics, services provided, and current medications. Diabetes was defined by diagnostic codes; patients with ischemic heart disease or younger than 30 years were excluded. We estimated national visit volumes by extrapolation using NAMCS sampling weights. Independent determinants of prevention practices were evaluated using multiple logistic regression. Actual visits sampled translated into an estimated 407 million office visits in 1995 and 1996, of which 44.8 million (11%) were by patients with diabetes. Overall, patients with diabetes received more cardiovascular disease prevention services than patients without diabetes, including cholesterol reduction (8% vs 5%, P <.001) and exercise counseling (22% vs 13%, P <.001), blood pressure measurement (82% vs 72%, P <.001), and aspirin prescription (5% vs 2%, P <.001). Patients with diabetes and hyperlipidemia were more likely to receive lipid-lowering medications than patients without these diagnoses (67% vs 51%, P =.007), but those who had diabetes and hypertension or who smoked were no more likely than those without to receive antihypertensive medications or smoking cessation counseling, respectively. These effects persisted in multiple logistic regression analyses controlling for potential confounders.

CONCLUSIONS

Patients with diabetes visiting U.S. physicians in 1995 and 1996 received somewhat more cardiovascular disease prevention services than patients without diabetes. Absolute rates of services, however, remained lower than desired based on national recommendations. Current evidence suggests that wider implementation of these recommendations can be expected to reduce the burden of cardiovascular disease in patients with diabetes.

Aspirin use is low among United States outpatients with coronary artery disease

BACKGROUND

The goal of the present study was to assess national trends and patterns of aspirin use among outpatients with coronary artery disease. Although there is strong evidence that the use of aspirin reduces the risk of death and recurrent events in patients with coronary artery disease, current national patterns of aspirin use are unknown.

METHODS AND RESULTS

We used data from the 1980 to 1996 National Ambulatory Medical Care Surveys. These surveys provide a nationally representative sample of physician activities during patient visits to physician offices. We evaluated the report of aspirin as a new or continuing medication in 10 942 visits to cardiologists and primary care physicians by patients with coronary artery disease. We evaluated trends in the use of aspirin for 1980 to 1996 and used logistic regression to identify independent predictors of aspirin use for 1993 to 1996. Aspirin use in outpatient visits by persons with coronary artery disease without reported contraindications increased from 5.0% in 1980 to 26.2% in 1996. Large increases occurred in the early 1990s. Independent predictors of aspirin use in 1993 to 1996 were male patient gender (29% versus 21% for females), patient age of <80 years (28% versus 17% for age of >/=80 years), and presence of hyperlipidemia (45% versus 24% for patients without hyperlipidemia; all comparisons P<0. 001). Cardiologists (37%) were more likely to report aspirin use than were internists (20%), family physicians (18%), or general practitioners (11%; P<0.001). These effects persisted after we controlled for potential confounders with the use of logistic regression.

CONCLUSIONS

Although aspirin use in patients with coronary artery disease has increased dramatically, it remains suboptimum. Low rates of aspirin use and variations in use suggest a need to better translate clinical recommendations into practice.

Age-specific patterns of prostate-specific antigen testing among primary care physician visits

BACKGROUND

Early detection of prostate cancer is thought to be effective, and indirect evidence suggests that men aged 50 to 69 years will benefit most while those aged 70 and older will benefit least from it. The goal of our study was to describe usual care patterns for prostate-specific antigen (PSA) testing by primary care physicians in the United States.

METHODS

We analyzed office visits made by adult men to family physicians, general internists, general practitioners, and geriatricians recorded by the 1995 and 1996 National Ambulatory Medical Care Surveys. Our outcome measure was the probability of a primary care physician ordering a PSA test during a visit.

RESULTS

Seventeen percent of the tests reported were among men aged younger than 50 years, 50% were for men aged 50 to 69 years, and 33% were for men aged 70 years and older. The frequency of PSA testing was highest during visits by men aged 60 to 64 years (7.1%), 65 to 69 years (7.0%), 70 to 74 years (7.0%), and 75 to 79 years (6.3%) but lower for men aged older than 80 years (3.1%).

CONCLUSIONS

Our findings suggest that during the mid-1990s prostate cancer screening decisions by primary care physicians were not sensitive to patients' ages.

Stress testing: national patterns and predictors of test ordering

OBJECTIVE

To determine predictors of ordering of exercise stress tests.

BACKGROUND

Because exercise stress testing is routinely used and widely available and may have an effect on subsequent evaluation of and therapy for heart disease, understanding current patterns of ordering exercise stress tests may have important implications for national health care costs. We hypothesized that factors other than clinical condition exert an influence on ordering of exercise stress tests.

METHODS

Data from the 1991 and 1992 National Ambulatory Medical Care Surveys conducted by the National Center for Health Statistics were analyzed by means of multivariate logistic regression.

RESULTS

In an estimated 1.12 billion adult visits to office-based physicians in the United States (95% confidence interval [CI], 1.07-1.16 billion), 6.2 million (95% CI, 4.8-7.6 million) exercise stress tests were ordered. After adjustment for clinical and nonclinical variables associated with the office visit, cardiologists were 3.7 (95% CI, 2.7-5.1) times more likely to order exercise stress tests than were internists, who were more likely to order an exercise stress test than were family and general practitioners (0.5, 95% CI, 0.3-0.7). Nonclinical factors associated with increased ordering of exercise stress tests included male sex (odds ratio 2.5; 95% CI, 2.0-3.2), white race (odds ratio 1.6; 95% CI, 1.1-2.3), new referral status (odds ratio 3.8; 95% CI, 2.5-5.8), and private insurance (odds ratio 1.4; 95% CI, 1.1-1.8). Medicare recipients were about half (95% CI, 0.4-0.9) as likely as other patients to have an exercise stress test ordered.

CONCLUSIONS

Factors other than clinical condition exert an influence on ordering of exercise stress tests and may represent modifiable elements associated with appropriate practice.

Rates of U.S. physicians counseling adolescents about smoking

BACKGROUND

The health care system provides an important opportunity for addressing tobacco use among youths, but there is little information about how frequently physicians discuss smoking with their adolescent patients. We analyzed data from the National Ambulatory Medical Care Surveys to assess the prevalence and the predictors of physicians' identification of smoking status and counseling about smoking at office visits by adolescents.

METHODS

From 1991 through 1996, 5087 physicians recorded data on 16 648 visits by adolescents aged 11-21 years. We determined the proportion of office visits at which physicians identified an adolescent's smoking status and counseled about smoking and then identified predictors of these outcomes with logistic regression. Statistical tests were two-sided.

RESULTS

In 1991, physicians identified an adolescent's smoking status at 72.4% of visits but provided smoking counseling at only 1.6% of all adolescent visits and 16.9% of visits by adolescents identified as smokers. These proportions did not increase from 1991 through 1996. Compared with specialists, primary care physicians were more likely to identify smoking status (odds ratio [OR] = 1.70; 95% confidence interval [CI] = 1.53-1.89) and to counsel about smoking (OR = 3.43; 95% CI = 2.18-5.38). Patients with diagnoses of conditions potentially complicated by smoking were more likely to have their smoking status identified and to be counseled about smoking. Younger and nonwhite adolescents were less likely to be counseled about smoking than older and white teens.

CONCLUSIONS

We found that physicians frequently identified adolescents' smoking status but rarely counseled them about smoking. Physicians' practices did not improve in the first half of the 1990s, despite a clear consensus about the importance of this activity and the publication of physician guidelines targeting this population. Physicians treating adolescents are missing opportunities to discourage tobacco use among teens.

Distinguishing chronic prostatitis and benign prostatic hyperplasia symptoms: results of a national survey of physician visits

OBJECTIVES

The morbidity of chronic prostatitis results from a constellation of genitourinary symptoms. A recent study classified 21 of these symptoms into three categories: pain, voiding complaints, and sexual dysfunction. Pain symptoms predominated among patients with prostatitis. Using data from a nationwide survey of physician visits, we examined the most common symptoms reported by men at chronic prostatitis visits and contrasted the results with visits for benign prostatic hyperplasia (BPH).

METHODS

We analyzed 81,034 visits by men (18 years and older) to office-based physicians of all specialties in the National Ambulatory Medical Care Surveys of 1990 to 1996, using sampling weights to make national estimates. U.S. physicians selected by random stratified sampling completed visit forms that included patients' reasons for visits and physicians' diagnoses.

RESULTS

In 1990 to 1996, there were 765 visits (national estimate 1.5 million visits/yr; 95% confidence interval = 0.9 to 2.1) with a diagnosis of chronic prostatitis. Among chronic prostatitis visits, 20% were for pain, 19% for urinary symptoms, and 1% for sexual dysfunction. Among 2271 BPH visits, 2% were for pain, 33% for voiding complaints, and 1% for sexual dysfunction. The most common reason coded for chronic prostatitis visits was painful urination (14% of chronic prostatitis visits, but only 1.7% of BPH visits).

CONCLUSIONS

Pain was slightly more common than voiding complaints, but much more common than sexual dysfunction among chronic prostatitis visits. The most common reason for chronic prostatitis visits was painful urination, which was uncommon among patients with BPH. Pain distinguished chronic prostatitis from BPH better than any other urinary symptom.

Trends in antihypertensive drug advertising, 1985-1996

BACKGROUND

Over the past decade, calcium channel blockers (CCBs) and ACE inhibitors have been used increasingly in the treatment of hypertension. In contrast, beta-blocker and diuretic use has decreased. It has been suggested that pharmaceutical marketing has influenced these prescribing patterns. No objective analysis of advertising for antihypertensive therapies exists, however.

METHODS AND RESULTS

We reviewed the January, April, July, and October issues of the New England Journal of Medicine from 1985 to 1996 (210 issues). The intensity of drug promotion was measured as the proportion of advertising pages used to promote a given medication. Statistical analyses used the chi2 test for trend. Advertising for CCBs increased from 4.6% of advertising pages in 1985 to 26.9% in 1996, while advertising for beta-blockers (12.4% in 1985 to 0% in 1996) and diuretics (4.2% to 0%) decreased (all P<0.0001). A nonsignificant increase was observed in advertising for ACE inhibitors (3.5% to 4.3%, P=0.17). Although the total number of drug advertising pages per issue decreased from 60 pages in 1985 to 42 pages in 1996 (P<0.001), the number of pages devoted to calcium channel blocker advertisements nearly quadrupled.

CONCLUSIONS

Increasing promotion of CCBs has mirrored trends in physician prescribing. An association between advertising and prescribing patterns could explain why CCBs have supplanted better-substantiated therapies for hypertension.

Trends in adult visits to primary care physicians in the United States

BACKGROUND

Although numerous changes are apparent in the US health care system, little is known about how these changes have altered the work of primary care physicians.

METHODS

We analyzed a nationally representative sample of 136,233 adult office visits to general internists, general practitioners, and family physicians contained in the 1978 through 1981, 1985, and 1989 through 1994 National Ambulatory Medical Care Surveys. Annual sample sizes varied between 5662 and 19,977 visits. Measures included the characteristics of patients presenting to primary care physicians, physician activities during these visits, and the disposition of the visits to primary care physicians.

RESULTS

Visits to primary care physicians have diminished as a proportion of all adult visits from 52% in 1978 to 41% in 1994. Dramatic trends in adult primary care included the growing racial or ethnic diversity of patients, the doubling (since 1985) of health maintenance organization coverage, increased provision of prevention services, changes in the most common medications, and an 18% increase in the duration of adult visits to primary care physicians.

CONCLUSIONS

Trends in primary care practice reflect changes in society and in the US health care system, including demographic changes, an emphasis on prevention, and the growth of managed care. The increasing role of managed care, with its emphasis on increased productivity, appears at odds with primary care physicians' increasing responsibility for prevention and the associated increase in the duration of primary care visits.

Specialty differences in cardiovascular disease prevention practices

OBJECTIVES

The aim of this study was to examine physician specialty differences in cardiovascular disease prevention practices.

BACKGROUND

Despite the importance of cardiovascular disease prevention, little is known about current national practices, particularly physician specialty differences.

METHODS

Using a national survey of office visits, we evaluated differences in the propensity of physicians of different specialties to provide prevention services. We analyzed 30,929 adult visits to 1,521 physicians selected by stratified random sampling in the 1995 National Ambulatory Medical Care Survey. Standard and ordinal multiple logistic regression models were employed to estimate the independent effects of physician and patient characteristics.

RESULTS

A variety of cardiovascular disease prevention services were provided during an estimated 547 million adult office visits to US physicians in 1995, including blood pressure measurement (50% of visits), cholesterol testing (5%) and counseling for exercise (12%), weight (6%), cholesterol (4%) and smoking (3%). In addition, medication management was reflected by the report of antihypertensives in 12% of visits and lipid-lowering medications in 2%. Across these eight services, propensity to provide services varied consistently with specialty. Controlling for patient and visit characteristics and compared to general internists, the likelihood of providing services was higher for cardiologists (adjusted odds ratio 1.65, 95% confidence interval 1.44 to 1.89) but lower for obstetrician/gynecologists (0.75, 0.68 to 0.82), family physicians (0.69, 0.64 to 0.74), general practitioners (0.58, 0.53 to 0.63), other medical specialists (0.65, 0.59 to 0.72) and surgeons (0.06, 0.05 to 0.06).

CONCLUSIONS

Cardiologists have the greatest propensity to provide cardiovascular disease prevention services, while primary care physicians vary substantially in their practices. These findings suggest a need to address variations in cardiovascular disease prevention.

Rate control and sinus rhythm maintenance in atrial fibrillation: national trends in medication use, 1980-1996

BACKGROUND

Little is known about national patterns of pharmacological treatment of atrial fibrillation, in particular, use of medications for ventricular rate control and for restoration and maintenance of sinus rhythm.

METHODS

We analyzed 1555 visits by patients with atrial fibrillation to randomly selected office-based US physicians included in National Ambulatory Medical Care surveys conducted in 1980, 1981, 1985, and 1989 through 1996. To determine national trends, we evaluated the proportion of atrial fibrillation visits with reported use of rate control medications (digoxin and antiarrhythmics in classes II and IV) and sinus rhythm medications (classes IA, IC, and III).

RESULTS

The use of rate control agents decreased from 79% of atrial fibrillation visits in 1980-1981 to 62% in 1994-1996. Declining use was noted for both digoxin (76% in 1980-1981 to 53% in 1994-1996) and beta-blockers (19%-13%). After their introduction, the use of verapamil hydrochloride and diltiazem hydrochloride increased to 15% of atrial fibrillation visits in 1994-1996. Sinus rhythm agent use decreased from 18% of visits in 1980-1981 to 4% in 1992-1993 and then rose to 13% in 1994-1996. The use of class IA agents declined from 18% in 1980-1981 to 3.5% in 1992-1993 and then increased to 8% in 1994-1996. Quinidine remained the most widely used sinus rhythm medication, despite its declining share of this category. Newly available sotalol hydrochloride and amiodarone hydrochloride were used in 3.6% of visits in 1994-1996.

CONCLUSIONS

Despite changes in the treatment of atrial fibrillation, digoxin remains the dominant rate control medication. Medications for sinus rhythm maintenance are not widely used. Quinidine use declined prominently in the 1980s, possibly because of concerns about proarrhythmic effects. The use of sinus rhythm agents, however, is now rising.

The declining impact of race and insurance status on hormone replacement therapy

OBJECTIVE

Socioeconomic barriers may limit the adoption of hormone replacement therapy, but little is known about recent trends in their influence. We evaluated trends in the impact of race and insurance status on national rates of hormone replacement therapy.

DESIGN

We analyzed 32,608 physician office visits by nonpregnant women 40 years of age and older available from the 1989 through 1996 National Ambulatory Medical Care Surveys. The proportion of visits with new or continuing use of noncontraceptive estrogens reported was the main outcome measured. Multiple logistic regression was used to evaluate the independent effects of year, race, and expected payment source on hormone replacement therapy.

RESULTS

Overall, the report of hormone replacement therapy increased from 5.7% of visits in 1989-1990 to 10.9% in 1995-1996. In 1989-1990, hormone replacement therapy was less likely in nonwhite women (3.6% vs. 6.3% for whites) and in women with Medicaid coverage (1.3% vs. 8.4% for privately insured women). These differences diminished over time, particularly for women without menopausal symptoms. In 1989-1990, the adjusted odds ratio of hormone replacement in women without menopausal symptoms was 0.31 (95% confidence interval 0.2-0.5) in nonwhites compared with whites, but increased to 0.57 (0.4-0.8) by 1995-1996. In 1989-1990, the adjusted odds ratio for hormone replacement among women with Medicaid was 0.31 (0.09-1.0) compared with those with private insurance. This ratio increased to 0.86 (0.5-1.4) by 1995-1996.

CONCLUSIONS

Racial and payment source influences on hormone replacement therapy appeared to have lessened over time. Despite these changes substantial socioeconomic differences in treatment patterns remain to be addressed.

National patterns and predictors of beta-blocker use in patients with coronary artery disease

BACKGROUND

Prior studies suggest underuse of beta-blockers in patients with coronary artery disease, but these studies have been based on selected populations of recently hospitalized patients.

OBJECTIVE

To describe national patterns and determinants of beta-blocker use in the ambulatory setting.

METHODS

We analyzed 11745 visits by patients with coronary artery disease to randomly selected, office-based physicians in the National Ambulatory Medical Care Surveys for 1980, 1981, 1985, and 1989 through 1996. We used multiple logistic regression to determine the independent effect of sociodemographic and clinical factors on beta-blocker use.

OUTCOME MEASURE

Beta-blocker use at patient visits.

RESULTS

Beta-blocker use was reported in only 20.9% of office visits by patients with coronary artery disease and no strong contraindications between 1993 and 1996. In multivariate analyses, age younger than 75 years, residence in the Northeast, and visits to cardiologists and internists compared with family and general practitioners predicted greater use of beta-blocker therapy. White race and private insurance also were significant predictors of beta-blocker use between 1980 and 1996. Longitudinal analyses revealed a significant decline in beta-blocker use from 1980 to 1990, followed by a gradual increase in recent years.

CONCLUSIONS

Beta-blockers appear to be underused in ambulatory patients with coronary artery disease. Our data suggest that nonclinical factors may influence rates of use, indicating the need for closer scrutiny of variations in physician prescribing practices.

National trends in the use of antibiotics by primary care physicians for adult patients with cough

BACKGROUND

Increased antibiotic use for outpatient illnesses has been identified as an important determinant of the recent rise in antibiotic resistance among common respiratory pathogens. Efforts to reduce the inappropriate use will need to be evaluated against current trends in the outpatient use of antibiotics.

OBJECTIVES

To examine national trends in the use of antibiotics by primary care physicians in the care of adult patients with cough and identify patient factors that may influence antibiotic use for these patients.

METHODS

This study was based on a serial analysis of results from all National Ambulatory Medical Care Surveys beginning in 1980 (when therapeutic drug use was first recorded) to 1994 (the most recent survey year available). These surveys are a random sampling of visits to US office-based physicians in 1980, 1981, 1985, and annually from 1989-1994. Eligible visits included those by adults presenting to general internists, family practitioners, or general practitioners with a chief complaint of cough. A total of 3416 visits for cough were identified over the survey years. Survey results were extrapolated, based on sampling weights in each year, to project national rates of antibiotic use for patients with cough. Additional analyses examined the rates of antibiotic use stratified by patient age, race, and clinical diagnosis.

RESULTS

Overall, an antibiotic was prescribed 66% of the time during office visits for patients with cough: 59% of patient visits in 1980 rising to 70% of visits in 1994 (P = .002 for trend). In every study year, white, non-Hispanic patients and patients younger than 65 years were more likely to receive antibiotics compared with nonwhite patients and patients 65 years or older, respectively.

CONCLUSIONS

The rate of antibiotic use by primary care physicians for patients with cough remained high from 1980 to 1994, and was influenced by nonclinical characteristics of patients.

Recent national patterns of warfarin use in atrial fibrillation

BACKGROUND

Studies of selected populations suggest that anticoagulation in atrial fibrillation is underused and that nonclinical factors influence the use of this stroke-preventing therapy. We wished to examine recent national trends and predictors of warfarin sodium use in atrial fibrillation.

METHODS AND RESULTS

A nationally representative sample of office visits from the 1989 to 1996 National Ambulatory Medical Care Surveys was used. We selected 1125 visits by patients with atrial fibrillation, including 877 visits to cardiologists and primary care physicians in which apparent contraindications for anticoagulation were absent. The principal outcome measure was the proportion of visits with warfarin reported. We analyzed trends in warfarin use and statistically evaluated the predictors of warfarin use. Warfarin use increased from 13% of atrial fibrillation visits in 1989 to 40% in 1993 (P for trend <.001) in patients without contraindications. Between 1993 and 1996, however, there was no change in warfarin use. Independent of other factors, warfarin was significantly more likely to be reported in patients with a history of stroke and in patients residing outside of the South.

CONCLUSIONS

Warfarin use in atrial fibrillation has not increased recently, indicating inadequate implementation of this highly effective therapy. Barriers to anticoagulation in real-world clinical practice need to be identified and addressed.

How common is prostatitis? A national survey of physician visits

PURPOSE

We used a national data base to explore the epidemiology of physician visits for genitourinary symptoms or a diagnosis of prostatitis.

MATERIALS AND METHODS

We analyzed 58,955 visits by men 18 years old or older to office based physicians of all specialties, as included in the National Ambulatory Medical Care Surveys from 1990 to 1994. Physicians selected by random sampling completed visit forms that included information on patient reasons for visits and physician diagnoses.

RESULTS

From 1990 to 1994, 5% of all ambulatory visits by men 18 years old or older included genitourinary symptoms as a reason for the visit. In almost 2 million visits annually prostatitis was listed as a diagnosis, including 0.7 million by men 18 to 50 years old and 0.9 million by those older than 50 years. Of the prostatitis visits 46 and 47% were to urologists and primary care physicians, respectively. A prostatitis diagnosis was assigned at 8 and 1% of all urologist and primary care physician visits, respectively. The odds of a prostatitis diagnosis were 13-fold greater at visits to urologists compared with visits to primary care physicians, and approximately 2-fold greater in the south than in the northeast. Surprisingly, compared with men 66 years old or older, prostatitis was more commonly diagnosed in men 36 to 65 than men 18 to 35 years old. When a prostatitis diagnosis was given, antimicrobial use was likely to be reported 45% of the time for men with and 27% for those without genitourinary symptoms. Visits to primary care physicians were more often associated with antimicrobial use than visits to urologists.

CONCLUSIONS

Genitourinary symptoms are a frequent reason for office visits by younger and older men, and prostatitis is a common diagnosis. Despite a report that less than 10% of prostatitis cases are bacterial, a much higher proportion of men in whom prostatitis is diagnosed receive antimicrobials.

Changes in the daily practice of primary care for children

BACKGROUND

The environment in which medicine is practiced has changed in the past 2 decades, but little information has been available on how the day-to-day practice of primary care for children has changed during this period.

OBJECTIVE

To identify aspects of primary care practices for children that are undergoing substantial changes.

DESIGN

Analysis of National Ambulatory Medical Care Surveys from 1979 to 1981, 1985, and 1989 to 1994.

PARTICIPANTS

Primary care practitioners recorded data on 58,488 child visits. MAIN OUT COME MEASURES: Characteristics and insurance status of children, physician activities during visits, and disposition after visit.

RESULTS

Child visits to primary care physicians increased by 22% between 1979 and 1994. The mean age of children visiting primary care physicians decreased from 6.7 years in 1979 to 5.7 years in 1994 (P for trend, < .001). The ethnic diversity of child visits increased primarily as a result of an increasing proportion of visits by Hispanic (6.0% in 1979 to 12.6% in 1994, P for trend, < .001) and Asian patients (1.6% in 1979 to 4.1% in 1994, P for trend, < .001). Medicaid and managed care increased dramatically as sources of payment. Changes in physician activities included an increase in some preventive services, changes in the most commonly encountered medications, and an increased mean duration of patient visits (11.8 minutes in 1979 to 14.2 minutes in 1994, P for trend, < .001).

CONCLUSIONS

These data may assist in the development of educational and research initiatives for physicians caring for children. The declining proportion of adolescent visits may present physicians with challenges in the care of adolescents. Physician prescribing practices showed changes without evidence of a benefit to child health. The increased ethnic diversity and provision of preventive services were associated with an increased mean duration of primary care visits. The increased duration of child visits may conflict with the managed care emphasis on physician productivity.

National patterns in the treatment of smokers by physicians

CONTEXT

Routine treatment of smokers by physicians is a national health objective for the year 2000, a quality measure for health care plans, and the subject of evidence-based clinical guidelines. There are few national data on how physicians' practices compare with these standards.

OBJECTIVE

To assess recent trends in the treatment of smokers by US physicians in ambulatory care and to determine whether physicians' practices meet current standards.

DESIGN

Analysis of 1991-1995 data from the National Ambulatory Medical Care Survey, an annual survey of a random sample of US office-based physicians.

SETTING

Physicians' offices.

PATIENTS

A total of 3254 physicians recorded data on 145716 adult patient visits.

MAIN OUTCOME MEASURES

The proportion of visits at which physicians (1) identified a patient's smoking status, (2) counseled a smoker to quit, and (3) used nicotine replacement therapy.

RESULTS

Smoking counseling by physicians increased from 16% of smokers' visits in 1991 to 29% in 1993 (P<.001) and then decreased to 21% of smokers' visits in 1995 (P<.001). Nicotine replacement therapy use followed a similar pattern, increasing from 0.4% of smokers' visits in 1991 to 2.2% in 1993 (P<.001) and decreasing to 1.3% of smokers' visits in 1995 (P=.007). Physicians identified patients' smoking status at 67% of all visits in 1991; this proportion did not increase over time. Primary care physicians were more likely to provide treatment to smokers than were specialists. All physicians were more likely to treat patients with smoking-related diagnoses.

CONCLUSIONS

US physicians' treatment of smokers improved little in the first half of the 1990s, although a transient peak in counseling and nicotine replacement use occurred in 1993 after the introduction of the nicotine patch. Physicians' practices fell far short of national health objectives and practice guidelines. In particular, patient visits for diagnoses not related to smoking represent important missed opportunities for intervention.

National patterns of angiotensin-converting enzyme inhibitor use in congestive heart failure

BACKGROUND

While the use of angiotensin-converting enzyme (ACE) inhibitors for patients with congestive heart failure (CHF) is supported by the results of clinical trials and expert guidelines, national physician practices are unknown.

METHODS

We analyzed 1529 physician office visits by patients with CHF available from the 1989 through 1994 National Ambulatory Medical Care Surveys. We examined changes over time in the use of ACE inhibitors and use of other medications for CHF. Potential clinical and nonclinical predictors of use of ACE inhibitors were evaluated using multiple logistic regression.

RESULTS

The prevalence of CHF increased from 0.9% of all office visits in 1989 to 1.1% in 1994. Use of ACE inhibitors increased from 24% in visits by patients with CHF in 1989 to 31% in 1994 (P = .02). From 1989 through 1994, use of ACE inhibitors was more likely in visits to cardiologists (46% vs 22% for all other physicians), in the Midwest (31% vs 24% in all other regions), in whites (27% vs 21% in nonwhites), in privately insured patients (31% vs 24% in all others), and in men (29% vs 23% in women). Multiple logistic regression analysis showed independent effects of specialty, region, and sex. Other medications commonly used for patients with CHF included diuretics (62% of visits for 1989-1994), digoxin (38%), and calcium channel antagonists (15%). Use of diuretics showed no significant trend between 1989 and 1994, whereas use of digoxin decreased significantly.

CONCLUSION

The low rates of use of ACE inhibitors in patients with CHF and the wide variations in their use suggest a need to move beyond clinical trials and focus attention on modifying physician practices.

The impact of cancer on the physical function of the elderly and their utilization of health care

BACKGROUND

Controversy about whether cancer has an independent impact on patient quality of life led the authors to evaluate the effects of cancer on a range of quality-of-life and health care utilization measures within an elderly population.

METHODS

The authors analyzed a nationally representative sample of 9745 elderly community-based Medicare beneficiaries sampled in the 1991 Medicare Current Beneficiary Survey. Of these, 1647 reported being diagnosed by a physician as having a malignancy that was not of the skin. Multiple logistic regression was used to identify the independent predictors of functional limitation, poor health status, health care utilization, and patient satisfaction with medical care.

RESULTS

Cancer was reported by 17% of the elderly. Individuals with cancer reported poorer health, more limitations of the activities of daily living (ADLs) and the instrumental activities of daily living (IADLs), and greater health care utilization than individuals without cancer. For individuals with cancer, difficulty walking (38%) and getting out of a chair (21%) were the most commonly reported ADL limitations, whereas difficulty completing heavy housework (34%) and shopping (17%) were the most common IADL limitations. Carcinomas of the lung, prostate, and colon independently predicted poorer health status. Lung carcinoma was independently associated with more ADL limitations. Lung, bladder, and prostate carcinomas predicted increased health care utilization. Overall, cancer patients were at least as satisfied with their medical care as those without cancer.

CONCLUSIONS

Cancer increased the use of health care resources and modestly reduced physical function. By identifying specific connections between cancer and physical function, these findings have implications for improving cancer care.

Low rates of hormone replacement in visits to United States primary care physicians

Our objective was to determine national rates and predictors of hormone replacement therapy. We analyzed a nationally representative sample of 6341 office visits by women aged > or = 40 years to primary care physicians in the 1993 and 1994 National Ambulatory Medical Care Surveys. Independent predictors of estrogen use were determined by logistic regression. Time trends from 1989 through 1994 also were evaluated. Hormone replacement therapy was documented in 4.7% of visits in 1989 to 1990 and 8.0% in 1993 to 1994. In 1993 to 1994 women with menopausal symptoms were six times more likely to have hormone replacement reported. In the absence of symptoms, obstetrician-gynecologists were nearly four times as likely to report hormone replacement therapy. Age 50 to 59 years, white race, osteoporosis, hyperlipidemia, and residence in the West and in nonmetropolitan areas also independently-predicted hormone replacement. Low rates of estrogen therapy by non-obstetrician-gynecologists and substantial practice variations suggest missed opportunities for hormone replacement therapy.

Variations in cholesterol management practices of U.S. physicians

OBJECTIVES

This study sought to evaluate national cholesterol management practices of U.S. physicians.

BACKGROUND

Past studies show that nonclinical factors affect physician practices. We tested the hypothesis that physician and patient characteristics influence cholesterol management.

METHODS

We used a stratified, random sample of 2,332 office-based physicians providing 56,215 visits to adults in the 1991-1992 National Ambulatory Medical Care Surveys. We investigated physicians' reporting of cholesterol-related screening, counseling or medications during office visits and used multiple logistic regression to assess independent predictors.

RESULTS

An estimated 1.12 billion adult office visits occurred in 1991 and 1992 (95% confidence interval 1.06 to 1.18 billion). For the 1.03 billion visits by patients without reported hyperlipidemia, cholesterol screening (2.8% of visits) and counseling (1.2%) were not frequent. The likelihood of screening increased with older age, cardiovascular disease risk factors, white race and private insurance. We estimate that only 1 in 12 adults received cholesterol screening annually. In the 85 million visits by patients with hyperlipidemia, cholesterol testing was reported in 22.9%, cholesterol counseling in 34.4% and lipid-lowering medications in 23.1%. Testing was more likely in diabetic and nonobese patients. Counseling was more likely with younger age, cardiovascular disease and private insurance. Medications use was associated with cardiovascular disease, Northeast region of the United States, nonobese patients and visits to internists. Physician practices did not differ by patient gender.

CONCLUSIONS

Although clinical conditions strongly influence cholesterol management, the appropriateness of variations noted by payment source, geographic region and physician specialty deserve further evaluation. These variations and the low estimated volume of services suggest that physicians have not fully adopted recommended cholesterol management practices.

National patterns of warfarin use in atrial fibrillation

BACKGROUND

Despite consensus that patients with atrial fibrillation benefit from warfarin sodium anticoagulation, little is known about national trends and predictors of anticoagulant use.

METHODS

We analyzed 1062 visits by patients with atrial fibrillation to randomly selected office-based physicians included in the National Ambulatory Medical Care Surveys in 1980, 1981, 1985, and 1989 through 1993. Warfarin and aspirin use in these patients was extrapolated to national patterns and logistic regression was used to determine independent predictors.

RESULTS

Patients with atrial fibrillation made an estimated 1.3 (1980) to 3.1 (1992) million annual visits to physicians. Warfarin use in atrial fibrillation increased from 7% in 1980 and 1981 to 32% in 1992 and 1993 (P < .001 for trend). In 1992 and 1993, patients 80 years or older were significantly less likely to be taking warfarin (19%) compared with younger patients (36%), but showed similar rates of increase from 1980 and 1981 to 1992 and 1993. In 1992 and 1993, anticoagulation therapy was significantly more likely to be reported in visits to cardiologists (32%) and general internists (40%) compared with general and family practitioners (15%), but was similar in women (34%) and men (30%). Residents of the South (16%) had significantly lower rates of warfarin use than those in other regions of the United States (36%). Aspirin use increased from 3% to 10% (P = .001 for trend) and showed little overlap with warfarin use. Multiple logistic regression indicated that more recent year, residence outside the South, patient aged 65 to 74 years, and visits to cardiologists and internists increased the likelihood of warfarin use.

CONCLUSIONS

Anticoagulant use for atrial fibrillation has increased dramatically. The substantial increase from 1989 and 1990 to 1992 and 1993 coincided with the publication of several randomized clinical trials reporting the benefits of warfarin. Although it is unrealistic to expect universal warfarin use, the 1992 and 1993 rate of 32% is probably suboptimal given the benefit of anticoagulation in preventing embolic strokes. The oldest patients, in whom warfarin may have its greatest benefit, appear to have the lowest rates of anticoagulant use.

Trends in cesarean section use in California, 1983 to 1990

OBJECTIVE

Our aim was to assess recent trends in cesarean section use in California.

STUDY DESIGN

California discharge abstract data on hospital deliveries in 1983 through 1990 (379,759 to 587,508 annual deliveries) were used to analyze time trends by indication, age, race, and payment source.

RESULTS

California cesarean section rates increased annually from 21.8% in 1983 to 25.0% in 1987 and then decreased to 22.7% by 1990. Similar patterns were noted for all age and race or ethnicity groups. Primary cesarean section rates increased from 15.2% in 1983 to 17.9% in 1987, then decreased to 16.2% by 1990. Declines in repeat cesarean section rates continued throughout 1983 through 1990, accelerating after 1987. For both primary and repeat cesarean section rates, time trends after mid-1987 were significantly different than those for 1983 to 1987.

CONCLUSION

After increasing from 1983 to 1987, California cesarean section rates declined from 1988 to 1990. Existing payment source differences in cesarean section use increased in magnitude from 1983 to 1990, with privately insured women consistently having the highest cesarean section rates.

HIV infection among patients in U.S. acute care hospitals. Strategies for the counseling and testing of the hospital patients. The Hospital HIV Surveillance Group

BACKGROUND

Routine, voluntary testing of hospital patients for the human immunodeficiency virus (HIV) has been proposed in order to identify those with early HIV infection in a setting where there is ready access to counseling, appropriate clinical referral, evaluation, and therapy. We studied the pattern of HIV infection among patients in 20 U.S. hospitals, in order to evaluate possible national strategies for the routine, voluntary HIV counseling and testing of hospital patients.

METHODS

Blood specimens remaining after clinical use from a systematically selected sample of patients at 20 hospitals in 15 U.S. cities were tested anonymously for antibody to HIV type 1 (HIV-1). Multivariate regression was used to determine which variables best predicted HIV seroprevalence in individual hospitals. Using these data, we estimated the number of HIV-positive patients in all U.S. hospitals and considered the efficiency of routine counseling and testing in different subgroups of patients and hospitals.

RESULTS

From September 1989 through October 1991, 9286 of 195,829 specimens (4.7 percent) were positive for HIV-1 in the 20 hospitals. The seroprevalence of HIV at these institutions ranged from 0.2 percent to 14.2 percent. Among HIV-positive patients, 32 percent had symptomatic HIV infection or the acquired immunodeficiency syndrome (AIDS) at the time of admission or evaluation. In the 20 hospitals, HIV seroprevalence was 10.4 times (95 percent confidence interval, 8.8 to 12.0) the AIDS-diagnosis rate (the annual number of patients with new diagnoses of AIDS per 1000 discharges in 1990). In a multivariate model that included 13 hospital-specific variables, only the AIDS-diagnosis rate was associated with the hospital-specific HIV-seroprevalence rate (P less than 0.001). Using these data and the AIDS-diagnosis rates for all U.S. acute care hospitals, we estimated that 225,000 HIV-positive persons were hospitalized (95 percent confidence interval, 190,000 to 260,000) in all 5558 such hospitals in 1990, including 163,000 persons presenting with conditions other than HIV or AIDS (95 percent confidence interval, 130,000 to 196,000). In 1990, in 593 U.S. hospitals with AIDS-diagnosis rates of 1.0 or more per 1000 discharges, HIV testing of patients 15 to 54 years old (3 million patients, or 12.0 percent of all patients in U.S. acute care hospitals) would have identified an estimated 68 percent of all HIV-positive patients (110,000 patients) who were admitted with conditions other than symptomatic HIV infection or AIDS.

CONCLUSIONS

We estimate that about 225,000 HIV-positive persons were hospitalized in 1990, of whom only one third were admitted for symptomatic HIV infection or AIDS. Routine, voluntary HIV testing of patients 15 to 54 years old in hospitals with 1 or more patients with newly diagnosed AIDS per 1000 discharges per year could potentially have identified as many as 110,000 patients with HIV infection that was previously unrecognized.

The impact of nonclinical factors on repeat cesarean section

Nonclinical factors, including the setting in which health care takes place, influence clinical decisions. This research measures the independent effects of organizational and socioeconomic factors on repeat cesarean section use in California. Of 45,425 births to women with previous cesarean sections in 1986, vaginal birth after cesarean section occurred in 10.9%. Sizable nonclinical variations were noted. By hospital ownership, rates ranged from 4.9% (for-profit hospitals) to 29.2% (University of California). Variations also existed by hospital teaching level (nonteaching hospitals, 7.0%, vs formalized teaching hospitals, 23.3%); payment source (private insurance, 8.1%, vs indigent services, 25.2%); and obstetric volume (low-volume hospitals, 5.4%, vs high-volume hospitals, 16.6%). Multiple logistic regression demonstrated that these variables had independent effects after accounting for their overlapping influences and the effects of patient characteristics. The observed variations demonstrate the prominence of nonclinical factors in decision making and question the clinical appropriateness of current practice patterns.

Recent trends in cesarean section use in California

Cesarean section use in the United States has increased to 24.7% of deliveries in 1988 and is the most common hospital surgical procedure. California cesarean section rates were examined to measure recent trends in obstetric practices and to project future patterns of cesarean section use. Using discharge abstracts from 1983 to 1987 California hospital deliveries, total cesarean section rates were found to increase from nearly 22% in 1983 to 25% in 1987, an increase of 15%. Using a series of least-squares regression models, time trends in the distribution of indications associated with cesarean section among all deliveries and indication-specific cesarean section rates were evaluated. Increases in the number of women with previous cesarean section and fetal distress contributed to rising cesarean section rates. In addition, indication-specific cesarean section rates increased for breech presentation and dystocia. These trends were counterbalanced, in part, by declining rates of repeat cesarean sections. Trends noted for July 1985 through 1987 did not differ substantially from those observed for January 1983 to June 1985, suggesting that recent policy attempts to alter cesarean section use have not had a measurable effect on existing trends. Projections suggest that California cesarean section rates will rise to a level of 34% by the year 2000.

Cesarean section use and source of payment: an analysis of California hospital discharge abstracts

This study assessed the relation between payment source and cesarean section use by analyzing California data on hospital deliveries. Of 461,066 deliveries in 1986, cesarean sections were performed in 24.4 percent. Women with private insurance had the highest cesarean section rates (29.1 percent). Successively lower rates were observed for women covered by non-Kaiser health maintenance organizations (26.8 percent), Medi-Cal (22.9 percent), Kaiser (19.7 percent), self-pay (19.3 percent), and Indigent Services (15.6 percent). Vaginal birth after cesarean (VBAC) occurred more than twice as frequently in women covered by Kaiser (19.9 percent) and Indigent Services (24.8 percent), compared to those with private insurance (8.1 percent). Sizable, although less pronounced, associations between payment source and cesarean section use were noted for the indications of breech presentation, dystocia, and fetal distress. Accounting for maternal age and race/ethnicity did not alter these findings. Variations in the use of cesarean section have a substantial financial impact on health care payors.

Alternative strategies for controlling rising cesarean section rates

Cesarean section rates in the United States have increased from 5.5% in 1970 to 24.4% in 1987. This dramatic increase has generated considerable concern, leading to a variety of proposals to control rising use of cesarean section. Six strategies have been adopted or proposed to reduce cesarean section use: (1) education and peer evaluation, (2) external review, (3) public dissemination of cesarean section rates, (4) changes in physician payment, (5) changes in hospital payment, and (6) medical malpractice reform. These strategies differ in their specific assumptions regarding the process of clinical decision making, implications for physician autonomy, and methods of implementation. Educational efforts have been the most widely promoted. Of these, formal programs aimed at modifying practices within individual hospitals appear to be the most successful. However, insufficient research has been conducted to compare conclusively the impact and feasibility of these six strategies, pointing to the need for further study.

Socioeconomic differences in rates of cesarean section

Increasing cesarean-section rates have focused attention on variations in the use of this procedure that appear to be independent of medical indication. We investigated the relation between the rate of primary cesarean section and socioeconomic status in a cohort of 245,854 singleton infants born to non-Hispanic white, black, Asian-American, and Mexican-American residents of Los Angeles County, California. On the basis of birth-certificate data for 1982 and 1983, a significant relation, independent of maternal age, parity, or birth weight, was found between the rates of primary cesarean section and socioeconomic status. Women who lived in census tracts with a median family income of more than $30,000 had a primary cesarean-section rate of 22.9 percent, as compared with 13.2 percent among women residing in areas with a median family income under $11,000. In women between the ages of 18 and 34, the incidence of reported complications of pregnancy or childbirth in the lowest-income group was 10.9 percent, as compared with 17.4 percent in the highest-income group (accounting for 42 percent of the difference in the rate of primary cesarean section between groups); the rate of primary cesarean section in the presence of complications in these two groups was 65.4 percent and 79.3 percent (accounting for 17 percent of the difference); and the primary rate in the absence of reported complications in these two groups was 6.4 percent and 10.5 percent (accounting for 41 percent of the difference). The rates of primary cesarean section were highest among non-Hispanic whites (20.6 percent), intermediate among Asian Americans (19.2 percent) and blacks (18.9 percent), and lowest among Mexican Americans (13.9 percent). Significant socioeconomic differences in these rates were observed in all four groups (P less than 0.01). We conclude that the rates of primary cesarean section vary directly with socioeconomic status and that this association cannot be accounted for by differences in maternal age, parity, birth weight, race, ethnic group, or complications of pregnancy or childbirth.