Beta agonists, inhaled steroids, and the risk of intensive care unit admission for asthma

Although inhaled corticosteroid (ICS) use is associated with a decreased risk of hospitalization for asthma, the impact of ICS on the risk of life-threatening asthma exacerbation is less clear. The effect of ICS and inhaled beta agonist (IBA) dispensing on the risk of intensive care unit admission for asthma, a surrogate for life-threatening exacerbation, is evaluated. Using computerized International classification of diseases (ICD)-9 discharge diagnoses, a cohort of all 2,344 adult Northern California members of a health maintenance organization hospitalized for asthma over a 2-yr period were identified. Computerized pharmacy data was used to ascertain asthma medications dispensed during the 3-,6-, and 12-month intervals preceding index hospitalization for asthma. During the 3-months preceding hospitalization, a minority of subjects had no IBA units dispensed (34%), with 14% receiving low level (1 unit), 20% medium level (2-3 units), and 32% high level (> or = 4 units) therapy. A substantial proportion received no ICS units (55%), whereas 13% had low, 16% medium, and 15% high level therapy. In multiple logistic regression analysis, high level IBA use was associated with a greater risk of intensive care unit (ICU) admission for asthma after controlling for asthma severity. There was no relationship, however, between low or medium level IBA use and ICU admission. Conversely, medium level and high level ICS use were associated with a reduced risk of ICU admission. Analysing 6- and 12-month medication dispensing data, similar risk patterns were observed. Inhaled corticosteroid dispensing was associated with reduced risk of intensive care unit admission among adults hospitalized for asthma, whereas the opposite applied for high dose beta agonist usage. This suggests that ICS prescription to adults with moderate-to-severe asthma could reduce the risk of life-threatening exacerbation.

Effect of physician and patient gender concordance on patient satisfaction and preventive care practices

OBJECTIVE

To explore the role of the gender of the patient and the gender of the physician in explaining differences in patient satisfaction and patient-reported primary care practice.

DESIGN

Crosssectional mailed survey [response rate of 71%].

SETTING

A large group-model Health Maintenance Organization (HMO) in northern California.

PATIENTS/PARTICIPANTS

Random sample of HMO members aged 35 to 85 years with a primary care physician. The respondents (N = 10,205) were divided into four dyads: female patients of female doctors; male patients of female doctors; female patients of male doctors; and male patients of male doctors. Patients were also stratified on the basis of whether they had chosen their physician or had been assigned.

MEASUREMENTS AND MAIN RESULTS

Among patients who chose their physician, females who chose female doctors were the least satisfied of the four groups of patients for four of five measures of satisfaction. Male patients of female physicians were the most satisfied. Preventive care and health promotion practices were comparable for male and female physicians. Female patients were more likely to have chosen their physician than males, and were much more likely to have chosen female physicians. These differences were not seen among patients who had been assigned to their physicians and were not due to differences in any of the measured aspects of health values or beliefs.

CONCLUSIONS

Our study revealed differences in patient satisfaction related to the gender of the patient and of the physician. While our study cannot determine the reasons for these differences, the results suggest that patients who choose their physician may have different expectations, and the difficulty of fulfi11ing these expectations may present particular challenges for female physicians.

The outcome and cost of alcohol and drug treatment in an HMO: day hospital versus traditional outpatient regimens

OBJECTIVE

To compare outcome and cost-effectiveness of the two primary addiction treatment options, day hospitals (DH) and traditional outpatient programs (OP) in a managed care organization, in a population large enough to examine patient subgroups.

DATA SOURCES

Interviews with new admissions to a large HMO's chemical dependency program in Sacramento, California between April 1994 and April 1996, with follow-up interviews eight months later. Computerized utilization and cost data were collected from 1993 to 1997.

STUDY DESIGN

Design was a randomized control trial of adult patients entering the HMO's alcohol and drug treatment program (N = 668). To examine the generalizability of findings as well as self-selection factors, we also studied patients presenting during the same period who were unable or unwilling to be randomized (N = 405). Baseline interviews characterized type of substance use, addiction severity, psychiatric status, and motivation. Follow-up interviews were conducted at eight months following intake. Breathanalysis and urinalysis were conducted. Program costs were calculated.

DATA COLLECTION

Interview data were merged with computerized utilization and cost data.

PRINCIPAL FINDINGS

Among randomized subjects, both study arms showed significant improvement in all drug and alcohol measures. There were no differences overall in outcomes between DH and OP, but DH subjects with midlevel psychiatric severity had significantly better outcomes, particularly in regard to alcohol abstinence (OR = 2.4; 95% CI = 1.2, 4.9). The average treatment costs were $1,640 and $895 for DH and OP programs, respectively. In the midlevel psychiatric severity group, the cost of obtaining an additional person abstinent from alcohol in the DH cohort was approximately $5,464. Among the 405 self-selected subjects, DH was related to abstinence (OR = 2.1; 95% CI = 1.3, 3.5).

CONCLUSIONS

Although significant benefits of the DH program were not found in the randomized study, DH treatment was associated with better outcomes in the self-selected group. However, for subjects with mid-level psychiatric severity in both the randomized and self-selected samples, the DH program produced higher rates of abstention and was more cost-effective. Self-selection in studies that randomize patients to services requiring very different levels of commitment may be important in interpreting findings for clinical practice.

Implications of stroke risk criteria on the anticoagulation decision in nonvalvular atrial fibrillation: the Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) study

BACKGROUND

Warfarin dramatically reduces the risk of stroke in patients with nonvalvular atrial fibrillation (NVAF) but increases the likelihood of bleeding. Accurately identifying patients who need anticoagulation is critical. We assessed the potential impact of prominent stroke risk classification schemes on this decision in a large sample of patients with NVAF.

METHODS AND RESULTS

We used clinical and electrocardiographic databases to identify 13 559 ambulatory patients with NVAF from July 1996 through December 1997. We compared the proportion of patients classified as having a low enough stroke risk to receive aspirin using published criteria from the Atrial Fibrillation Investigators (AFI), American College of Chest Physicians (ACCP), and the Stroke Prevention in Atrial Fibrillation Investigators (SPAF). In this cohort, AFI criteria classified 11% as having a low stroke risk, compared with 23% for ACCP and 29% for SPAF (kappa range, 0.44 to 0.85). This 2- to-3-fold increase in low stroke risk patients by ACCP and SPAF criteria primarily resulted from the inclusion of many older subjects (65 to 75 years+/-men >75 years) with no additional clinical stroke risk factors.

CONCLUSIONS

The age threshold for assigning an increased stroke risk has a dramatic impact on whether to recommend warfarin in populations of patients with NVAF. Large, prospective studies with many stroke events are needed to precisely determine the relationship of age to stroke risk in AF and to identify which AF subgroups are at a sufficiently low stroke risk to forego anticoagulation.

Heritability of factors of the insulin resistance syndrome in women twins

The insulin resistance syndrome (IRS) is characterized by a combination of interrelated coronary heart disease (CHD) risk factors, including low high-density lipoprotein cholesterol (HDL-C) levels, obesity and increases in triglyceride (TG), blood pressure, small low-density lipoprotein particles (LDL), and both fasting and postload plasma insulin and glucose. Using factor analysis, we previously identified 3 uncorrelated factors that explained 66% of the variance among these variables, based on data from women participating in examination 2 of the Kaiser Permanente Women Twins Study in Oakland, CA during 1989-1990. The factors were interpreted as: 1) body mass/fat distribution, 2) insulin/glucose, and 3) lipids: TG, HDL-C, LDL peak particle diameter. In this analysis, heritability of each of the factors was estimated based on data from 140 monozygotic and 96 dizygotic pairs of non-diabetic women twins. Heritability estimates were calculated using the classical approach, the analysis of variance (ANOVA) approach, and the maximum likelihood approach. For the body mass/fat distribution factor heritability estimates suggest moderate genetic influences; 0.61 (P < 0.001), 0.14 (P > 0.05), and 0.71 (P < 0.001), respectively. The insulin/glucose factor appeared to be highly heritable, with estimates of 0.87, 0.92, and 0.57 (all P < 0.001), respectively. The heritability estimates for the lipid factor were moderate and consistent across methods: 0.25 (P < 0.10), 0.32 (P < 0.05), and 0.30 (P < 0.05), respectively. These results are consistent with genetic influences on each of the 3 "factors," and suggest that both genetic and environmental effects are involved in the clustering of IRS risk factors.

Self-monitoring of blood glucose: language and financial barriers in a managed care population with diabetes

OBJECTIVE

Self-monitoring of blood glucose (SMBG) is a cornerstone of diabetes care, but little is known about barriers to this self-care practice.

RESEARCH DESIGN AND METHODS

This cross-sectional study examines SMBG practice patterns and barriers in 44,181 adults with pharmacologically treated diabetes from the Kaiser Permanente Northern California Region who responded to a health survey (83% response rate). The primary outcome is self-reported frequency of SMBG.

RESULTS

Although most patients reported some level of SMBG monitoring, 60% of those with type 1 diabetes and 67% of those with type 2 diabetes reported practicing SMBG less frequently than recommended by the American Diabetes Association (three to four times daily for type 1 diabetes, and once daily for type 2 diabetes treated pharmacologically). Significant independent predictors of nonadherent practice of SMBG included longer time since diagnosis, less intensive therapy, male sex, age, belonging to an ethnic minority, having a lower education and neighborhood income, difficulty communicating in English, higher out-of-pocket costs for glucometer strips (especially for subjects with lower incomes), smoking, and excessive alcohol consumption.

CONCLUSIONS

Considerable gaps persist between actual and recommended SMBG practices in this large managed care organization. A somewhat reduced SMBG frequency in subjects with linguistic barriers, some ethnic minorities, and subjects with lower education levels suggests the potential for targeted, culturally sensitive, multilingual health education. The somewhat lower frequency of SMBG among subjects paying higher out-of-pocket expenditures for strips suggests that removal of financial barriers by providing more comprehensive coverage for these costs may enhance adherence to recommendations for SMBG.

The cost of health conditions in a health maintenance organization

In this retrospective cohort analysis of all adults who were members of Kaiser Permanente, Northern California, between July 1995 and June 1996 (N = 2,076,303), the authors estimated the prevalence, average annual costs per person, and percentage of total direct medical expenditures attributable to each of 25 chronic and acute conditions. Ordinary least squares regression was used to adjust for age, gender, and comorbidities. The costs attributable to the 25 conditions accounted for 78 percent of the health maintenance organization's total direct medical expense for this age-group. Injury accounted for a higher proportion (11.5 percent) of expenditures than any other single condition. Three cardiovascular conditions--ischemic heart disease, hypertension, and congestive heart failure--together accounted for 17 percent of direct medical expense and separately accounted for 6.8 percent, 5.7 percent, and 4.0 percent, respectively. Renal failure ($22,636), colorectal cancer ($10,506), pneumonia ($9,499), and lung cancer ($8,612) were the most expensive conditions per person per year.

Racial and ethnic differences in a patient survey: patients' values, ratings, and reports regarding physician primary care performance in a large health maintenance organization

BACKGROUND

Few studies have investigated the influence of race and/or ethnicity on patients' ratings of quality of care. None have incorporated patients' values and beliefs regarding medical care in assessing these possible differences.

OBJECTIVES

We explored whether patients' values, ratings, and reports regarding physicians' primary care performance differed by race and/or ethnicity.

RESEARCH DESIGN

This was a cross-sectional, mailed patient survey.

SUBJECTS

The study subjects were adult primary care patients in a large health maintenance population (7,747 whites, 836 blacks, 710 Latinos, and 1,007 Asians). MEASURES AND METHODS: Ratings of the following dimensions of primary care were measured: technical competence, communication, accessibility, prevention and health promotion, and overall satisfaction. Patients' values regarding these dimensions and their confidence in medical care were measured. Multivariate analyses yielded associations of race/ethnicity with satisfaction and with reports of prevention services received.

RESULTS

For 7 of the 10 dimensions of primary care measured, Asians rated physician performance significantly less favorably than did whites, including differences among Asian ethnic subgroups. Latinos rated physicians' accessibility less favorably than did whites. Blacks rated physicians' psychosocial and lifestyle health promotion practices higher than did whites. No differences were found in patient reports of prevention services received, except Pacific Islanders reported receiving significantly more prevention services than whites.

CONCLUSIONS

In a large HMO population, significant differences were found by race and ethnicity, and among Asian ethnic subgroups, in levels of patient satisfaction with primary care. These findings may represent actual differences in quality of care or variations in patient perceptions, patient expectations, and/or questionnaire response styles. More research is needed to assess, in accurate and culturally appropriate ways, whether health plans are meeting the needs of all enrollees.

Warfarin use among ambulatory patients with nonvalvular atrial fibrillation: the anticoagulation and risk factors in atrial fibrillation (ATRIA) study

BACKGROUND

Warfarin dramatically reduces the risk for ischemic stroke in nonvalvular atrial fibrillation, but its use among ambulatory patients with atrial fibrillation has not been widely studied.

OBJECTIVE

To assess the rates and predictors of warfarin use in ambulatory patients with nonvalvular atrial fibrillation.

DESIGN

Cross-sectional study.

SETTING

Large health maintenance organization.

PATIENTS

13428 patients with a confirmed ambulatory diagnosis of nonvalvular atrial fibrillation and known warfarin status between 1 July 1996 and 31 December 1997.

MEASUREMENTS

Data from automated pharmacy, laboratory, and clinical-administrative databases were used to determine the prevalence and determinants of warfarin use in the 3 months before or after the identified diagnosis of atrial fibrillation.

RESULTS

Of 11082 patients with nonvalvular atrial fibrillation and no known contraindications, 55% received warfarin. Warfarin use was substantially lower in patients who were younger than 55 years of age (44.3%) and those who were 85 years of age or older (35.4%). Only 59.3% of patients with one or more risk factors for stroke and no contraindications were receiving warfarin. Among a subset of "ideal" candidates to receive warfarin (persons 65 to 74 years of age who had no contraindications and had previous stroke, hypertension, or both), 62.1% had evidence of warfarin use. Among our entire cohort, the strongest predictors of receiving warfarin were previous stroke (adjusted odds ratio, 2.55 [95% CI, 2.23 to 2.92]), heart failure (odds ratio, 1.63 [CI, 1.51 to 1.77]), previous intracranial hemorrhage (odds ratio, 0.33 [CI, 0.21 to 0.52]), age 85 years or older (odds ratio, 0.35 [CI, 0.31 to 0.40]), and previous gastrointestinal hemorrhage (odds ratio, 0.47 [CI, 0.40 to 0.57]).

CONCLUSIONS

In a large, contemporary cohort of ambulatory patients with atrial fibrillation who received care within a health maintenance organization, warfarin use was considerably higher than in other reported studies. Although the reasons why physicians did not prescribe warfarin could not be elucidated, many apparently eligible patients with atrial fibrillation and at least one additional risk factor for stroke, especially hypertension, did not receive anticoagulation. Interventions are needed to increase the use of warfarin for stroke prevention among appropriate candidates.

Warfarin use among ambulatory patients with nonvalvular atrial fibrillation: the anticoagulation and risk factors in atrial fibrillation (ATRIA) study

BACKGROUND

Warfarin dramatically reduces the risk for ischemic stroke in nonvalvular atrial fibrillation, but its use among ambulatory patients with atrial fibrillation has not been widely studied.

OBJECTIVE

To assess the rates and predictors of warfarin use in ambulatory patients with nonvalvular atrial fibrillation.

DESIGN

Cross-sectional study.

SETTING

Large health maintenance organization.

PATIENTS

13428 patients with a confirmed ambulatory diagnosis of nonvalvular atrial fibrillation and known warfarin status between 1 July 1996 and 31 December 1997.

MEASUREMENTS

Data from automated pharmacy, laboratory, and clinical-administrative databases were used to determine the prevalence and determinants of warfarin use in the 3 months before or after the identified diagnosis of atrial fibrillation.

RESULTS

Of 11082 patients with nonvalvular atrial fibrillation and no known contraindications, 55% received warfarin. Warfarin use was substantially lower in patients who were younger than 55 years of age (44.3%) and those who were 85 years of age or older (35.4%). Only 59.3% of patients with one or more risk factors for stroke and no contraindications were receiving warfarin. Among a subset of "ideal" candidates to receive warfarin (persons 65 to 74 years of age who had no contraindications and had previous stroke, hypertension, or both), 62.1% had evidence of warfarin use. Among our entire cohort, the strongest predictors of receiving warfarin were previous stroke (adjusted odds ratio, 2.55 [95% CI, 2.23 to 2.92]), heart failure (odds ratio, 1.63 [CI, 1.51 to 1.77]), previous intracranial hemorrhage (odds ratio, 0.33 [CI, 0.21 to 0.52]), age 85 years or older (odds ratio, 0.35 [CI, 0.31 to 0.40]), and previous gastrointestinal hemorrhage (odds ratio, 0.47 [CI, 0.40 to 0.57]).

CONCLUSIONS

In a large, contemporary cohort of ambulatory patients with atrial fibrillation who received care within a health maintenance organization, warfarin use was considerably higher than in other reported studies. Although the reasons why physicians did not prescribe warfarin could not be elucidated, many apparently eligible patients with atrial fibrillation and at least one additional risk factor for stroke, especially hypertension, did not receive anticoagulation. Interventions are needed to increase the use of warfarin for stroke prevention among appropriate candidates.

Evaluating hypertension control in a managed care setting

BACKGROUND

We conducted a retrospective cohort study on a random sample of adult patients with hypertension in a large health maintenance organization to assess the feasibility of documenting blood pressure (BP) control and to compare different measures for defining BP control.

METHODS

Three criteria for BP control were assessed: systolic BP less than 140 mm Hg; diastolic BP less than 90 mm Hg; and combined BP control, with systolic BP less than 140 mm Hg and diastolic BP less than 90 mm Hg. Four methods of assessing hypertension control by the above criteria were examined: proportion of patients with BP under control at 75% and 50% or more of their office visits; the mean of all pressures during the study period; and the BP from the last visit during the study period.

RESULTS

The proportion of patients meeting each criterion for control was similar whether we used the mean BP for all visits, the last recorded BP, or control at 50% or more of visits. Control rates were substantially lower when the more stringent assessment, 75% of visits, was used. The proportion of patients with combined BP control at 75% or more of their visits was half that of the other methods.

CONCLUSIONS

In this health maintenance organization population, results with the use of the simplest approach, the last BP measurement recorded, were similar to results with the mean BP. Our findings indicate that evaluation of BP control in a large health maintenance organization will find substantial room for improvement, and clinicians should be encouraged to be more aggressive in their management of hypertension, especially with regard to the systolic BP, which until recent years has been underemphasized.

Diabetes management in a health maintenance organization. Efficacy of care management using cluster visits

OBJECTIVE

To evaluate the effectiveness of a cluster visit model led by a diabetes nurse educator for delivering outpatient care management to adult patients with poorly controlled diabetes.

RESEARCH DESIGN AND METHODS

This study involved a randomized controlled trial among patients of Kaiser Permanente's Pleasanton, CA, center who were aged 16-75 years and had either poor glycemic control (HbA1c > 8.5%) or no HbA1c test performed during the previous year. Intervention subjects received multidisciplinary outpatient diabetes care management delivered by a diabetes nurse educator, a psychologist, a nutritionist, and a pharmacist in cluster visit settings of 10-18 patients/month for 6 months. Outcomes included change (from baseline) in HbA1c levels; self-reported changes in self-care practices, self-efficacy, and satisfaction; and utilization of inpatient and outpatient health care.

RESULTS

After the intervention, HbA1c levels declined by 1.3% in the intervention subjects versus 0.2% in the control subjects (P < 0.0001). Several self-care practices and several measures of self-efficacy improved significantly in the intervention group. Satisfaction with the program was high. Both hospital (P = 0.04) and outpatient (P < 0.01) utilization were significantly lower for intervention subjects after the program.

CONCLUSIONS

A 6-month cluster visit group model of care for adults with diabetes improved glycemic control, self-efficacy, and patient satisfaction and resulted in a reduction in health care utilization after the program.

Comparing individual-based and household-based measures of social class to assess class inequalities in women's health: a methodological study of 684 US women

STUDY OBJECTIVE

To describe and compare magnitude of class inequalities in women's health detected with four occupation-based class measures: individual, conventional household (male dominant), gender neutral household, and combined household.

DESIGN

Cross sectional study, using health data obtained by physical examination, laboratory analysis, and self report.

SETTING

A large pre-paid health maintenance organisation in Oakland, CA (US).

PARTICIPANTS

686 women (90% white) enrolled in Examination II of the Kaiser Permanente Women Twins Study (1989-1990).

MAIN RESULTS

The proportion of women categorised as "working class" equalled 45, 30, and 21 per cent, respectively, for the individual level, gender neutral household, and conventional household class measures. Class inequalities in health, comparing women categorised as working class with non-working class, generally were stronger using the gender neutral household class measure, compared with the conventional household or individual class measure; in the case of "fair or poor" health, the respective odds ratios and 95% confidence intervals (adjusted for age and marital status) were 1.9 (1.1, 3.4), 1.5 (0.9, 2.5), and 1.3 (0.8, 2.2), while for high post-load glucose levels, they were 1.7 (1.1, 2.6), 1.2 (0.8, 1.7), and 1.3 (0.9, 1.8). The combined household class measure yielded effect estimates comparable to those of the gender neutral household class measure but with less precision, because of smaller strata.

CONCLUSIONS

Epidemiological studies concerning class inequalities in women's health should use the gender neutral household class measure or, if sample size is sufficiently large, the combined household class measure.

Resolving the gatekeeper conundrum: what patients value in primary care and referrals to specialists

CONTEXT

Few data are available regarding how patients view the role of primary care physicians as "gatekeepers" in managed care systems.

OBJECTIVE

To determine the extent to which patients value the role of their primary care physicians as first-contact care providers and coordinators of referrals, whether patients perceive that their primary care physicians impede access to specialists, and whether problems in gaining access to specialists are associated with a reduction in patients' trust and confidence in their primary care physicians.

DESIGN, SETTING, AND PATIENTS

Cross-sectional survey mailed in the fall of 1997 to 12707 adult patients who were members of managed care plans and received care from 10 large physician groups in California. The response rate among eligible patients was 71%. A total of 7718 patients (mean age, 66.7 years; 32 % female) were eligible for analysis.

MAIN OUTCOME MEASURES

Questionnaire items addressed 3 main topics: (1) patient attitudes toward the first-contact and coordinating role of their primary care physicians, (2) patients' ratings of their primary care physicians (trust and confidence in and satisfaction with), and (3) patient perceptions of barriers to specialty referrals. Referral barriers were analyzed as predictors of patients' ratings of their physicians.

RESULTS

Almost all patients valued the role of a primary care physician as a source of first-contact care (94%) and coordinator of referrals (89%). Depending on the specific medical problem, 75% to 91% of patients preferred to seek care initially from their primary care physicians rather than specialists. Twenty-three percent reported that their primary care physicians or medical groups interfered with their ability to see specialists. Patients who had difficulty obtaining referrals were more likely to report low trust (adjusted odds ratio [OR], 2.7; 95% confidence interval [CI], 2.1-3.5), low confidence (OR, 2.2; 95% CI, 1.6-2.9), and low satisfaction (OR, 3.3; 95% CI, 2.6-4.2) with their primary care physicians.

CONCLUSIONS

Patients value the first-contact and coordinating role of primary care physicians. However, managed care policies that emphasize primary care physicians as gatekeepers impeding access to specialists undermine patients' trust and confidence in their primary care physicians.

Women's provider preferences for basic gynecology care in a large health maintenance organization

To examine women's preferences for the type and sex of the provider of basic gynecological services and the correlates of these preferences, we mailed a cross-sectional survey to 8406 women in a large group model health maintenance organization (HMO) in northern California, with a response rate of 73.6%. Four questions asked women the type (obstetrician/gynecologist, nurse practitioner, or primary care physician) and sex of provider who performed their last pelvic examination and their preferences in type and sex of provider for these examinations. This was a random sample of female HMO members 35-85 years of age who were empaneled with a primary care physician from one of three categories: family practitioner, general internist, or subspecialist. Of the 5164 respondents who received their last pelvic examination at Kaiser Permanente, 56% had seen a gynecologist, 26% a nurse practitioner, and only 18% their own primary care physician for the examination. Of these women, 60.3% reported preferring a gynecologist for basic gynecology care, 12.6% preferred a nurse practitioner, 13.3% preferred their own primary care physician, and 13.8% had no preference. Patients of family practitioners were more likely to prefer their own primary care practitioner than patients of other types of doctors. The strongest independent predictor of preferring a gynecologist over the primary care physician was having seen a gynecologist for the last pelvic examination (OR = 28.3, p < 0.0001). Other independent predictors of preferring a gynecologist were younger age, higher education and income, and having a male primary care physician. Of respondents, 52.2% preferred a female provider for basic gynecological care, and 42.0% had no preference for the sex of the provider. Preferring a female provider was strongly and independently associated with lower income, higher education, nonwhite race, having a male primary care physician, having an older primary care, physician, and having seen a female provider at the last pelvic examination. In this HMO, a majority of women reported a preference for seeing an obstetrician/gynecologist for their routine gynecological care, despite having a primary care physician. This most likely reflects the strong influence of previous patient experience and that familiarity with a particular type of provider leads to preferences for that type. This medical group's structure probably also affects preferences, as in this HMO, primary care physicians can be discouraged from performing pelvic examinations. Many women do prefer female providers for pelvic examinations, but a large percentage have no preference. These women often see male providers for basic gynecological care. As managed care places increasing emphasis on providing integrated, comprehensive primary care, this apparent preference for specialty gynecological care will require further study.

Quality of primary care practice in a large HMO according to physician specialty

OBJECTIVE

To determine whether physician specialty was associated with differences in the quality of primary care practice and patient satisfaction in a large, group model HMO.

DATA SOURCES/STUDY SETTING

10,608 patients ages 35-85 years, selected using stratified probability sampling from the primary care panels of 60 family physicians (FPs), 245 general internists (GIMs), and 55 subspecialty internists (SIMs) at 13 facilities in the Kaiser Permanente Medical Care Program of Northern California. Patients were surveyed in 1995.

STUDY DESIGN

A cross-sectional patient survey measured patient reports of physician performance on primary care measures of coordination, comprehensiveness, and accessibility of care, preventive care procedures, and health promotion. Additional items measured patient satisfaction and health values and beliefs.

PRINCIPAL FINDINGS

Patients were remarkably similar across physician specialty groups in their health values and beliefs, ratings of the quality of primary care, and satisfaction. Patients rated GIMs higher than FPs on coordination (adjusted mean scores 68.0 and 58.4 respectively, p<.001) and slightly higher on accessibility and prevention; GIMs were rated more highly than SIMs on comprehensiveness (adjusted mean scores 76.4 and 73.8, p<.01). There were no significant differences between specialty groups on a variety of measures of patient satisfaction.

CONCLUSIONS

Few differences in the quality of primary care were observed by physician specialty in the setting of a large, well-established group model HMO. These similarities may result from the direct influence of practice setting on physician behavior and organization of care or, indirectly, through the types of physicians attracted to a well-established group model HMO. In some settings, practice organization may have more influence than physician specialty on the delivery of primary care.

Differences in resource use and costs of primary care in a large HMO according to physician specialty

OBJECTIVE

To determine if primary care physician specialty is associated with differences in use of health services.

DATA SOURCES

Automated outpatient diagnostic, utilization, and cost data on 15,223 members (35-85 years of age) of a large group model HMO.

STUDY DESIGN

One-year prospective comparison of primary care provided by 245 general internists (GIMs), 60 family physicians (FPs), and 55 subspecialty internists (SIMs) with case-mix assessed during a nine-month baseline period using Ambulatory Diagnostic Groups.

PRINCIPAL FINDINGS

Adjusting for demographics and case mix, patients of GIMs and FPs had similar hospitalization and ambulatory visit rates, and similar laboratory and radiology costs. Patients of FPs made fewer visits to dermatology, psychiatry, and gynecology (combined visit rate ratio: 0.86, 95% CI: 0.74-0.96). However, they made more urgent care visits (rate ratio 1.19, 95% CI: 1.07-1.23). Patients of SIMs had higher hospitalization rates than those of GIMs (rate ratio 1.33, 95% CI: 1.06-1.68), greater use of urgent care (rate ratio: 1.14, 95% CI: 1.04-1.25), and higher costs for pharmacy (cost ratio: 1.17, 95% CI: 0.93-1.18) and radiologic services (cost ratio: 1.14, 95% CI: 1.01-1.30). The hospitalization difference was due partly to the inclusion of patients with specialty-related diagnoses in panels of SIMs. Radiology and pharmacy differences persisted after excluding these patients.

CONCLUSIONS

In this uniform practice environment, specialty differences in primary care practice were small. Subspecialists used slightly more resources than generalists. The broader practice style of FPs may have created access problems for their patients.

Excess maternal transmission of type 2 diabetes. The Northern California Kaiser Permanente Diabetes Registry

OBJECTIVE

To assess excess maternal transmission of type 2 diabetes in a multiethnic cohort. Previous studies have reported higher prevalence of diabetes among mothers of probands with type 2 diabetes than among fathers. This analysis is vulnerable to biases, and this pattern has not been observed in all populations or races.

RESEARCH DESIGN AND METHODS

We assessed evidence for excess maternal transmission among 42,533 survey respondents with type 2 diabetes (probands) by calculating the prevalence of diabetes in their siblings and offspring. To assess data quality, we evaluated completeness of family history data provided. Accuracy of family information reported by probands was also evaluated by comparing survey responses in a subsample of 206 probands with family histories modified after further interviews with relatives.

RESULTS

Siblings (n = 60,532) of probands with affected mothers had a greater prevalence of diabetes (20%) than those with affected fathers (17%) (P < 0.001 for adjusted odds ratios). Prevalence of diabetes was higher among the offspring (n = 72,087) of female (3.4%) versus male (2.2%) probands (P < 0.001 for adjusted odds ratios). These patterns were evident in all races and both sexes; however, the effect size was clinically insignificant in African-Americans and male offspring. In general, probands provided more complete data about diabetes status for the maternal arm of the pedigree than the paternal arm. Completeness of knowledge was not related to proband sex, but was related to education and race, and inversely to age. Accuracy of proband-reported family history was consistently good (kappa statistics generally > 0.70).

CONCLUSIONS

Excess maternal transmission was observed in all races and both sexes, although the size of the excess was negligible in African-Americans and male offspring. Potential reporting and censoring biases are discussed.

Predicting advanced proximal colonic neoplasia with screening sigmoidoscopy

CONTEXT

Indications are not well defined for follow-up colonoscopy for all patients with distal colonic tubular adenomas (TAs) found at screening sigmoidoscopy.

OBJECTIVE

To determine whether distal adenoma size, number, and villous histology, along with family history and age, are predictors of advanced proximal colonic neoplasia.

DESIGN

Cross-sectional analysis conducted between January 1, 1994, and December 31, 1995.

SETTING

Large group-model health maintenance organization in northern California.

PATIENTS

A total of 2972 asymptomatic subjects aged 50 years or older undergoing colonoscopy as follow-up to a screening sigmoidoscopy.

MAIN OUTCOME MEASURE

Based on sigmoidoscopy, colonoscopy, and pathology reports, occurrence of advanced proximal neoplasia, defined as adenocarcinoma or TAs 1 cm or larger or with villous features or severe dysplasia located beyond sigmoidoscopic view.

RESULTS

The prevalence of advanced proximal neoplasia was similar among patients with no TAs at sigmoidoscopy, those with TAs less than 1 cm in diameter, and those with TAs 1 cm in diameter or larger (prevalence, 5.3%, 5.5%, and 5.6%, respectively). Of patients with a distal tubulovillous or villous adenoma, 12.1% had advanced proximal neoplasia. In multivariate analyses, having a distal tubulovillous adenoma or villous adenoma was the strongest predictor of advanced proximal neoplasia (odds ratio, 2.30; 95% confidence interval, 1.69-3.14). Age of 65 years or older, having more than 1 adenoma, and a positive family history of colorectal cancer were also significant predictors. Distal adenoma size was not a significant predictor in any multivariate analyses.

CONCLUSIONS

Advanced proximal neoplasia is not uncommon in subjects with or without distal TAs, but subjects with advanced distal histology and those older than 65 years are at increased risk. Age-specific screening using sigmoidoscopy starting at ages 50 to 55 years and colonoscopy after age 65 years may be justified.

First 20 months' experience with use of metformin for type 2 diabetes in a large health maintenance organization

OBJECTIVE

To assess adherence to prescribing guidelines, continuation rates, population effects on glycemic control, and occurrence of lactic acidosis during the first 20 months of the availability of metformin in a large health maintenance organization.

RESEARCH DESIGN AND METHODS

A retrospective cohort study was performed in the 90,000-member diabetes registry of Kaiser Permanente, northern California. Principal study measures were the proportions of patients started on metformin who met prescribing guidelines (previously on sulfonylureas, HbA1c, obesity, creatinine), the change in HbA1c at 6 months after starting metformin, and hospitalization rates for lactic acidosis.

RESULTS

A total of 9,875 patients received metformin during this interval. At least 74% were previously treated with sulfonylureas alone, 81% had baseline HbA1c > or = 8.5%, 71% were obese, and 99% had a serum creatinine < or = 1.5 mg/dl. Among patients on sulfonylureas at baseline, those starting metformin had significantly lower HbA1c levels 6 months later than those not started, after adjustment for age, sex, and the higher baseline levels in those started (adjusted difference: 0.5%, P < 0.0001). Patients starting metformin as initial monotherapy also improved significantly, but patients previously treated with insulin (with or without sulfonyl-ureas) had slightly higher follow-up HbA1c levels than similar patients not starting metformin. Continuation of metformin at 12 months was significantly higher for patients previously treated with sulfonylureas than other groups. One probable case of lactic acidosis was identified during 4,502 person-years on metformin.

CONCLUSIONS

Adherence to prescribing guidelines was relatively high during metformin's first 20 months of availability. Glycemic control improved substantially for patients previously treated with sulfonylureas. Lactic acidosis was rare.

Genetic and behavioral determinants of waist-hip ratio and waist circumference in women twins

OBJECTIVES

This study examines genetic and behavioral determinants of waist-hip ratio (WHR) and waist circumference among women twins.

RESEARCH METHODS AND PROCEDURES

Six hundred eighty participants from the second examination of the Kaiser-Permanente Women Twins Study (1989 to 1990) were included. Women ranged in age from 31 to 90 years, and included 59% monozygotic and 41% dizygotic twins. Heritabilities of WHR and waist circumference were estimated (range=0 to 1) using three different statistical methods. Linear regression models that adjusted for the lack of independence within twin pairs were used to assess associations between behavioral variables, WHR, and waist circumference.

RESULTS

Age and body mass index-adjusted heritability estimates ranged from 0.36 to 0.61 for WHR and 0.72 to 0.82 for waist circumference. When considered individually, after adjusting for age and body mass index, all behavioral characteristics, except calorie-adjusted fat intake, were significantly (p<0. 10) associated with waist circumference and WHR. Greater central adiposity was associated with lower education, higher alcohol consumption, lower physical activity, current cigarette smoking, higher parity, and postmenopausal status without hormone replacement therapy. In multivariate models, these associations persisted, except neither educational attainment nor alcohol intake was significantly associated with waist circumference. In longitudinal analyses, both measures were positively associated with current or recent-past smoking; infrequent or inconsistent physical activity; and long-term, daily consumption of alcohol.

DISCUSSION

These cross-sectional and longitudinal associations are consistent with genetic and behavioral predictors of waist circumference and WHR. Whereas the evidence for genetic influences is stronger for waist circumference, both body fat measures may be similarly influenced by the behavioral factors considered.

Is colonoscopy needed for the nonadvanced adenoma found on sigmoidoscopy? The Polyp Prevention Trial

BACKGROUND & AIMS

The need for colonoscopy when small tubular adenomas with low-grade dysplasia are found on sigmoidoscopy is uncertain. The aim of this study was to examine the prevalence and characteristics of proximal adenomas in patients with distal adenomas.

METHODS

We studied 981 subjects with distal adenomas found on the index colonoscopy before randomization in the Polyp Prevention Trial.

RESULTS

Four hundred sixty patients (46.9%) had >/=1 distal adenoma that was pathologically advanced (villous component, high-grade dysplasia, or >/=1 cm); 21.5% (211 of 981) had any proximal adenoma; and 4.3% (42 of 981) (95% confidence interval [CI], 3.0-5.5) had an advanced proximal adenoma. A greater percentage of patients with an advanced distal adenoma (5.9%) (95% CI, 3.7-8.0) had an advanced proximal adenoma compared with those with a nonadvanced distal adenoma (2.9%) (95% CI, 1.4-4.3) (OR, 2.1; 95% CI, 1.1-4.3; P = 0.03). Not performing a colonoscopy in patients with a nonadvanced distal adenoma would have missed 36% (15 of 42) of the advanced proximal adenomas.

CONCLUSIONS

Patients with an advanced distal adenoma are twice as likely to have an advanced proximal adenoma as patients with a nonadvanced distal adenoma. However, eschewing a colonoscopy in patients with a nonadvanced distal adenoma would result in not detecting a sizeable percentage of the prevalent advanced proximal adenomas. These data support performance of a colonoscopy in patients with a nonadvanced distal adenoma. Confirmation of these results in asymptomatic subjects undergoing screening sigmoidoscopy is advisable.