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Biomedical subjects

C P Quesenberry

Publications and source records attributed to C P Quesenberry.

At least 19 recordsLinked to original sources

Pregnancy plasma glucose levels exceeding the American Diabetes Association thresholds, but below the National Diabetes Data Group thresholds for gestational diabetes mellitus, are related to the risk of neonatal macrosomia, hypoglycaemia and hyperbilirubinaemia.

AIMS/HYPOTHESIS: Gestational diabetes mellitus (GDM) is a risk factor for perinatal complications. In several countries, the criteria for the diagnosis of GDM have been in flux, the American Diabetes Association (ADA) thresholds recommended in 2000 being lower than those of the National Diabetes Data Group (NDDG) that have been in use since 1979. We sought to determine the extent to which infants of women meeting only the ADA criteria for GDM are at increased risk of neonatal complications. MATERIALS AND METHODS: In a multiethnic cohort of 45,245 women who did not meet the NDDG criteria and were not treated for GDM, we conducted nested case-control studies of three complications of GDM that occurred in their infants: macrosomia (birthweight >4,500 g, n = 494); hypoglycaemia (plasma glucose <2.2 mmo/l, n = 488); and hyperbilirubinaemia (serum bilirubin > or =342 micromol/l (20 mg/dl), n = 578). We compared prenatal glucose levels of the mothers of these infants and mothers of 884 control infants. RESULTS: Women with GDM by ADA criteria only (two or more glucose values exceeding the threshold) had an increased risk of having an infant with macrosomia (odds ratio OR = 3.40, 95% CI = 1.55-7.43), hypoglycaemia (OR = 2.61, 95% CI = 0.99-6.92) or hyperbilirubinaemia (OR = 2.22, 95% CI = 0.98-5.04). Glucose levels 1 h after the 100-g glucose challenge that exceeded the ADA threshold were particularly strongly associated with each complication. CONCLUSIONS/INTERPRETATION: These results lend support to the ADA recommendations and highlight the importance of the 1-h glucose measurement in a diagnostic test for GDM.

Blood Glucose↗

Excess gains in weight and waist circumference associated with childbearing: The Coronary Artery Risk Development in Young Adults Study (CARDIA).

OBJECTIVE: To examine the association of childbearing with weight and waist circumference (WC) changes, we compared women with and without pregnancies or births during follow-up. STUDY DESIGN: A multicenter, longitudinal observational study over 10 years. Comparison groups defined by the number of pregnancies and births during follow-up: P0 (0 pregnancies; nongravid), P1 (1+ miscarriages or abortions; 'short' pregnancies), B1 (1 birth), and B2 (2+ births). Mean changes in weight and WC for P1, B1 and B2 groups vs P0 were examined separately by race (black and white), baseline parity (nulliparous and parous) and baseline weight status (normal weight; BMI <25 kg/m(2) and overweight; BMI >/=25 kg/m(2)). SUBJECTS: A population-based sample of 2070 women aged 18-30 y at baseline (1053 black subjects and 1017 white subjects) from Birmingham, Alabama, Chicago, Illinois, Minneapolis, Minnesota, and Oakland, California were examined five times between 1985-1986 and 1995-1996. MEASUREMENTS: Weight and WC measurements were obtained using standardized protocol at baseline and examinations at years 2, 5, 7 and 10. Sociodemographic, reproductive, and behavioral attributes were assessed at baseline and follow-up examinations. RESULTS: Gains in weight and WC associated with pregnancy and childbearing varied by race (P<0.001), baseline parity (P<0.05) and overweight status (P<0.001). Among overweight nulliparas, excess gains in weight (black subjects: 3-5 kg, white subjects: 5-6 kg) and WC (black subjects: 3-4 cm, white subjects: 5-6 cm) were associated with 'short' pregnancies and one or more birth(s) during follow-up compared to no pregnancies (P<0.01 and 0.001). Among normal weight nulliparas, excess gains in weight (about 1 kg) and WC (2-3 cm) were associated with follow-up birth(s) (P<0.05). Among women parous at baseline, no excess weight gains were found, but excess WC gains (2-4 cm) were associated with follow-up births. CONCLUSION: Substantial excess weight gain is associated with both short pregnancies and a first birth in women overweight prior to initiation of childbearing. Excess weight gain was not associated with higher order births. Increases in waist girth were cumulative with both first and higher order births among overweight as well as normal weight women. Interventions to prevent obesity should be targeted at women who are overweight prior to initiation of childbearing. The impact of excess WC gains associated with childbearing on women's future health risk should be evaluated further.

Adolescent↗

Slow infusion for the prevention of akathisia induced by prochlorperazine: a randomized controlled trial.

The utility of intravenous prochlorperazine (PCZ) in the treatment of nausea, vomiting, and headache may be limited by the akathisia that occurs frequently with the recommended 2-min infusion rate. We tested the hypothesis that decreasing the rate of PCZ infusion to 15 min reduces the incidence of akathisia at 1 hour. This double-blinded, randomized, controlled trial was conducted in the Emergency Department of an academic tertiary-care medical center with an annual census of 95,000 emergency patient visits. We enrolled a convenience sample of adult patients who received 10 mg i.v. PCZ for the treatment of nausea, vomiting, or headache. Subjects were randomized to receive either a 2-min infusion of PCZ (10 mg) followed by a 15-min infusion of saline, or a 2-min infusion of saline followed by a 15-min infusion of prochlorperazine. The incidence of akathisia at 1 hour was measured by using explicit diagnostic criteria. One hundred sixty patients were randomly enrolled into two groups, which were comparable with respect to age, gender, weight, and complaint. Akathisia developed in 31 of 84 patients (36.9%) who received the 2-min infusion of PCZ and in 18 of 76 patients (23.7%) who received the 15-min infusion of PCZ (p = 0.07), a 36% (95% CI, -5% to 61%) relative reduction. The delta from pre-infusion to postinfusion scores between the two groups was not significant (p = 0.19). We conclude that slowing the rate of PCZ infusion does not decrease akathisia.

Adolescent↗

Impact of the change in polio vaccination schedule on immunization coverage rates: a study in two large health maintenance organizations.

OBJECTIVE: In January 1997, one of the most significant changes to United States vaccine policy occurred when polio immunization guidelines changed to recommend a schedule containing inactivated polio vaccine (IPV). There were concerns that parent or physician reluctance to accept IPV into the routine childhood immunization schedule would lead to lowered coverage. We determined whether adoption of an IPV schedule had a negative impact on immunization coverage. DESIGN: A cohort study of 2 large health maintenance organizations (HMOs), Group Health Cooperative and Kaiser Permanente Northern California, was conducted. For analysis at 12 months of age, children who were born between October 1, 1996, and December 31, 1997, and were commercially insured and covered by Medicaid were continuously enrolled; for analysis at 24 months of age, children who were born between October 1, 1996, and June 30, 1997, and were commercially insured and covered by Medicaid were continuously enrolled. The 3 measures of immunization status at 12 and 24 months of age were up-to-date status, cumulative time spent up-to-date, and the number of missed opportunity visits. RESULTS: At both HMOs, children who received IPV were as likely to be up to date at 12 months as were children who received oral poliovirus vaccine (OPV), whereas at Group Health, children who received IPV were slightly more likely to be up to date at 24 months (relative risk: 1.12; 95% confidence interval [CI]: 1.05, 1.19). These findings were consistent for children who were covered by Medicaid. At Kaiser Permanente, children who received IPV spent ~3 fewer days up to date in the first year of life, but this difference did not persist at 2 years of age. At Group Health, children who received IPV were no different from those who received OPV in terms of days spent up to date by 1 or 2 years of age. At Group Health, children who received IPV were less likely to have a missed opportunity by 12 months old (odds ratio [OR] 0.46; 95% CI: 0.31, 0.70), but this finding did not persist at 24 months of age. At Kaiser Permanente, children who received IPV were more likely to have a missed opportunity by 12 months (OR 2.06; 95% CI: 1.84, 2.30), and 24 months of age (OR 1.50; 95% CI: 1.36, 1.67). CONCLUSIONS: The changeover from an all-OPV schedule to one containing IPV had little if any negative impact on vaccine coverage. Use of IPV was associated with a small increase in the likelihood of being up to date at 2 years of age at one of the HMOs and conversely was associated with a small increase in the likelihood of having a missed-opportunity visit in the other HMO.polio, poliomyelitis, vaccination, immunization coverage.

California↗

Variation in clinician recommendations for multiple injections during adoption of inactivated polio vaccine.

OBJECTIVES: To describe variation in clinician recommendations for multiple injections during the adoption of inactivated poliovirus vaccine (IPV) in 2 large health maintenance organizations (HMOs), and to test the hypothesis that variation in recommendations would be associated with variation in immunization coverage rates. DESIGN: Cross-sectional study based on a survey of clinician practices 1 year after IPV was recommended and computerized immunization data from these clinicians' patients. STUDY SETTINGS: Two large West Coast HMOs: Kaiser Permanente in Northern California and Group Health Cooperative of Puget Sound. OUTCOME MEASURES: Immunization status of 8-month-olds and 24-month-olds cared for by the clinicians during the study. RESULTS: More clinicians at Group Health (82%), where a central guideline was issued, had adopted the IPV/oral poliovirus vaccine (OPV) sequential schedule than at Kaiser (65%), where no central guideline was issued. Clinicians at both HMOs said that if multiple injections fell due at a visit and they elected to defer some vaccines, they would be most likely to defer the hepatitis B vaccine (HBV) for infants (40%). At Kaiser, IPV users were more likely than OPV users to recommend the first HBV at birth (64% vs 28%) or if they did not, to defer the third HBV to 8 months or later (62% vs 39%). In multivariate analyses, patients whose clinicians used IPV were as likely to be fully immunized at 8 months old as those whose clinicians used all OPV. At Kaiser, where there was variability in the maximum number of injections clinicians recommended at infant visits, providers who routinely recommended 3 or 4 injections at a visit had similar immunization coverage rates as those who recommended 1 or 2. At both HMOs, clinicians who strongly recommended all possible injections at a visit had higher immunization coverage rates at 8 months than those who offered parents the choice of deferring some vaccines to a subsequent visit (at Kaiser, odds ratio [OR]: 1.2; 95% confidence interval [CI]: 1.0-1.5; at Group Health, OR: 1.8; 95% CI: 1.1-2.8). CONCLUSIONS: Neither IPV adoption nor the use of multiple injections at infant visits were associated with reductions in immunization coverage. However, at the HMO without centralized immunization guidelines, IPV adoption was associated with changes in the timing of the first and third HBV. Clinical policymakers should continue to monitor practice variation as future vaccines are added to the infant immunization schedule.

Child, Preschool↗

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.

Adult↗

Statistical process control geometric Q-chart for nosocomial infection surveillance.

Several authors have proposed the use of statistical process control charting methods for the surveillance of endemic rates of nosocomial infections. The principal goal of such a charting program is to recognize any increase of the endemic rate to an epidemic rate as soon as possible after the change occurs. However, many of the statistical process control charting methods that have been proposed are based on classical charting principles that are effective largely for processes for which sufficient historical data are available. These methods require that a fairly large data set, taken while the infection rate was stable at a low endemic value, must be available to begin the charting process. These data are used both to confirm the appropriateness of the probability distribution and to make a control chart for the infection process based on the distribution. However, such data sets are often not available. The purpose of this article is to inform and demonstrate to readers that recent research in statistics has developed modern statistical process control methods that can be used effectively with or without such prior data. These methods make possible much more effective nosocomial infection surveillance programs that will give timely warnings of the onsets of epidemics or evidence of the effectiveness of infection control initiatives. These warnings will permit earlier correction initiatives and thus avoid much liability.

Clostridioides difficile↗

Hormone replacement therapy and the risk of myocardial infarction in women with coronary risk factors.

To assess the risk of myocardial infarction in users of post-menopausal hormone replacement therapy who are at high risk of coronary disease because of hypertension, diabetes mellitus, or smoking, we used data from a previously published case-control study of women 45-74 years. After adjustment for age, ethnicity, and education, the odds ratio for myocardial infarction in current users of hormone replacement therapy was 0.9 (95% confidence interval (CI) = 0.5-1.6) in women with no major coronary risk factors, 0.8 (95% CI = 0.5-1.8) in women with one risk factor, and 1.1 (95% CI = 0.5-2.2) in women with two risk factors.

Aged↗

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.

Adult↗

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.

Acute Disease↗

Spousal concordance for cancer incidence: A cohort study.

BACKGROUND: Because married couples share at least their home environment, spousal aggregation of cancer might provide clues to unsuspected etiologic factors. The authors sought to measure the concordance of cancer occurrence in married couples and explore factors that might explain greater-than-expected concordance. METHODS: The authors identified 25,670 cancer-free married couples in northern California who were followed for up to 31 years for the development of cancer. In Cox proportional hazards analysis, the development of cancer in a spouse was treated as a time-dependent, independent variable, and spouse-with/spouse-without risk ratios were determined, controlling for age and gender. For selected concordant espoused pairs, additional explanatory information was sought in their medical records. RESULTS: There was no excess concordance for all cancers combined; the spouse-with/spouse-without risk ratio was 0.97 (95% confidence interval, 0.90-1.05). Statistically significant husband-wife associations were found only for cancer of the tongue and stomach and for non-Hodgkin lymphoma. Except for cancer of the penis/endometrium and testis/vulva, based on one couple with each combination, gender specific cancers did not aggregate within married couples. Established and suspected risk factors, not necessarily related to the marriage, were found for some individuals who had concordance with their spouses. CONCLUSIONS: Little spousal concordance for cancer occurrence was found. The study of spousal aggregation does not appear useful in identifying unsuspected environmental causes of cancer in heterogeneous populations in urban areas of affluent Western countries. A cohort study would have to be much larger than this one to detect weak spousal concordance reliably.

Adult↗

Association of total and central adiposity measures with fasting insulin in a biracial population of young adults with normal glucose tolerance: the CARDIA study.

OBJECTIVE: To determine the association of computed tomography (CT)-measured visceral adipose tissue (AT) and other measures of adiposity with fasting insulin in a biracial (African American and Caucasian) study population of young adults. RESEARCH METHODS AND PROCEDURES: The study population consisted of 251 young adults with normal glucose tolerance (NGT), ages 28-40 years, who were volunteers from the Birmingham, Alabama, and Oakland, California centers of the Coronary Artery Risk Development in Young Adults (CARDIA) study. RESULTS: In regression models with total adiposity measures (body mass index or dual-energy X-ray absorptiometry-measured percent fat), visceral AT (measured as a cross-sectional area in cm2) was generally a stronger predictor of insulin than overall adiposity in all race/gender groups (partial correlation coefficients ranging from 0.31 to 0.47) except for black men, in whom the associations were nonsignificant. Partial correlation coefficients between waist circumference and insulin, controlling for percent fat, were nearly identical to those between visceral AT and insulin in women and in white men. Analyses performed on 2060 NGT CARDIA subjects who were not in this study of visceral AT showed significant correlations of waist circumference with insulin in all race/gender groups, including black men, and that black men in the visceral AT study group were significantly leaner than other black male CARDIA subjects. DISCUSSION: We conclude that visceral AT was associated with fasting insulin in NGT participants in three of the four race/gender groups (black men excepted) and that waist circumference was a good surrogate for visceral AT in examining associations of central adiposity with fasting insulin.

Absorptiometry, Photon↗

Physical activity patterns in a diverse population of women.

BACKGROUND: Demographic and psychosocial correlates of activity in domains other than recreational activity have not been well characterized and may be particularly relevant for health promotion efforts aimed at women. METHODS: Cross-sectional relationships between recreational, occupational, and household/caregiving physical activity and demographic and psychosocial factors were assessed with a mail survey in a random sample of 2,636 ethnically diverse women members of a large health maintenance organization, ages 20-65. Activity was assessed with a modified Baecke questionnaire that uses categorical responses regarding frequency of domain-specific activities to create four semicontinuous activity indices (sports/exercise, active living, occupational, household/caregiving). RESULTS: Multivariable logistic regression analysis showed that the likelihood of being in the highest quartile of the sports/exercise and active-living indices, compared with the other three quartiles, was decreased among older, nonwhite, less well educated, heavier women who had young children at home, lacked motivation to exercise, and perceived external obstacles to exercise behavior. The odds ratios (ORs) ranged from 0.38, 95% confidence interval (CI) 0.33-0.45, associated with low motivation, to 0.95, 95% CI 0.93-0.98, associated with increasing body mass index. Social support and confidence in one's ability to continue to exercise, even when faced with other pressures and demands (termed self-efficacy), were associated with increased likelihood of high levels of sports/exercise and active living (OR = 2.34, 95% CI 1. 83-2.98 and OR = 3.96, 95% CI 2.92-5.38, respectively). In contrast, the highest quartile of household/caregiving activity was positively associated with increasing age (OR = 1.28, 95% CI 1.16-1.42), Hispanic ethnicity (OR = 1.58, 95% CI 0.55-1.01), being married (OR = 1.70, 95% CI 1.33-2.18), having young children at home (OR = 6.99, 95% CI 4.33-11), and greater time constraints as a barrier to exercise (OR = 1.55, 95% CI 1.38-1.74) and was negatively associated with employment (OR = 0.38, 95% CI 0.30-0.47). Increased likelihood of the highest quartile of occupational activity was associated with high school education or less (OR = 2.26, 95% CI 1.74-2.94) and current smoking (OR = 1.66, 95% CI 1.23-2.23), while self-efficacy regarding exercise was associated with decreased likelihood (OR = 0. 77, 95% CI 0.61-0.96). CONCLUSIONS: These findings suggest that demographic and psychosocial correlates of physical activity vary by domain and that initiatives to promote physical activity in the population need to take these differences into account.

Adult↗

Computer-based models to identify high-risk adults with asthma: is the glass half empty of half full?

This study developed and evaluated the performance of prediction models for asthma-related adverse outcomes based on the computerized hospital, clinic, and pharmacy utilization databases of a large health maintenance organization. Prediction models identified patients at three- to four-fold increased risk of hospitalization and emergency department visits, and were valid for test samples from the same population. A model that identified 19% of patients as high risk had a sensitivity of 49%, a specificity of 84%, and a positive predictive value of 19%. We conclude that prediction models that are based on computerized utilization data can identify adults with asthma at elevated risk, but may have limited sensitivity and specificity in actual populations.

Adult↗

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.

Adult↗

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.

Adult↗

Comparison of the Block and the Willett self-administered semiquantitative food frequency questionnaires with an interviewer-administered dietary history.

The performances of two commonly used diet instruments, the Block and the Willett food frequency questionnaires, were compared with a longer, interviewer-administered diet history. Participants in a case-control study on diet and colon cancer were interviewed between 1990 and 1994 in northern California, Utah, and Minnesota by trained nutritionists using a validated diet history. Two separate subsamples of participants were asked to complete either the Block or the Willett questionnaire exactly 5 days after they completed the original diet history. Data were analyzed separately by subsample comparing either the Block or the Willett questionnaire with the original diet history by using means, correlations, quintile agreement, and odds ratios for the relation between several nutrients and colon cancer. The Block and the Willett questionnaires generally provided lower absolute intake estimates than did the original diet history; however, the Block questionnaire underestimated more than did that by Willett. Both correlations and quintile agreement were slightly better for the Willett questionnaire than for that by Block when compared with the original diet history. In general, point estimates obtained from either the Block or the Willett questionnaire fell within the confidence intervals of the estimates of the odds ratios obtained from the original diet history, and no real difference in significance levels appeared. Although the Block and Willett questionnaires differed slightly from each other and from our original diet history in estimating absolute nutrients and ranking or classifying individuals, they were very similar in their ability to predict disease outcome.

Adult↗