Biomedical subjects

C Quesenberry

Publications and source records attributed to C Quesenberry.

7 recordsLinked to original sources

PubMed1999

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.

Aged↗

PubMed1999

Social class, race/ethnicity, and incidence of breast, cervix, colon, lung, and prostate cancer among Asian, Black, Hispanic, and White residents of the San Francisco Bay Area, 1988-92 (United States).

BACKGROUND: To date only eight US studies have simultaneously examined cancer incidence in relation to social class and race/ethnicity; all but one included only black and white Americans. To address gaps in knowledge we thus investigated socioeconomic gradients in cancer incidence among four mutually exclusive US racial/ethnic groups-- Asian and Pacific Islander, black, Hispanic, and white-- for five major cancer sites: breast, cervix, colon, lung, and prostate cancer. METHODS: We generated age-adjusted cancer incidence rates stratified by socioeconomic position using: (a) geocoded cancer registry records, (b) census population counts, and (c) 1990 census block-group socioeconomic measures. Cases (n = 70,899) were diagnosed between 1988 and 1992 and lived in seven counties located in California's San Francisco Bay Area. RESULTS: Incidence rates varied as much if not more by socioeconomic position than by race/ethnicity, and for each site the magnitude - and in some cases direction - of the socioeconomic gradient differed by race/ethnicity and, where applicable, by gender. Breast cancer incidence increased with affluence only among Hispanic women. Incidence of cervical cancer increased with socioeconomic deprivation among all four racial/ethnic groups, with trends strongest among white women. Lung cancer incidence increased with socioeconomic deprivation among all but Hispanics, for whom incidence increased with affluence. Colon and prostate cancer incidence were inconsistently associated with socioeconomic position. CONCLUSIONS: These complex patterns defy easy generalization and illustrate why US cancer data should be stratified by socioeconomic position, along with race/ethnicity and gender, so as to improve cancer surveillance, research, and control.

Adolescent↗

PubMed1998

Statistical methods in epidemiology: a comparison of statistical methods to analyze dose-response and trend analysis in epidemiologic studies.

Evaluation of various statistical methods to describe accurately associations between exposures and disease are constantly being explored. Spline regression has been suggested as an alternative to using categorized variables in studies of disease etiology, as it uses all data points to estimate the shape of the association between a given exposure and disease outcome. It has been proposed that this method is especially beneficial when associations are concentrated in a small range of the overall distribution of the exposure. In this study, we use data from a large case-control study of colon cancer to evaluate associations obtained from logistic regression models that use spline regression for main exposure and confounder effects with those that use categorized variables for main exposure. Our results show that for variables for which the association appears to be linear, such as body size and dietary intake of calcium, fiber, and cholesterol, associations are similar when estimates are generated from spline or categorized variable models. For other variables, such as total energy intake, for which associations appear to be strongest in the upper end of the distribution, estimates of association appear to be conservative when using categorized variables. The data also suggest that selection of cut points for the categorized variables may have an impact on the associations observed. Spline regression appears to be useful to estimate the shape of the association between a given exposure and disease and may provide guidance as to the appropriateness of using categorized variables. The risk estimates from spline regression appear to be similar to those from traditional categorical methods. When effects are large or rapidly changing, spline models may more appropriately describe the association.

Adult↗

PubMed1998

Stroke and cocaine or amphetamine use.

The association of cocaine and amphetamine use with hemorrhagic and ischemic stroke is based almost solely on data from case series. The limited number of epidemiologic studies of stroke and use of cocaine and/or amphetamine have been done in settings that serve mostly the poor and/or minorities. This case-control study was conducted in the defined population comprising members of Kaiser Permanente of Northern and Southern California. We attempted to identify all incident strokes in women ages 15-44 years during a 3-year period using hospital admission and discharge records, emergency department logs, and payment requests for out-of-plan hospitalizations. We selected controls, matched on age and facility of usual care, at random from healthy members of the health plan. We obtained information in face-to-face interviews. There were 347 confirmed stroke cases and 1,021 controls. The univariate matched odds ratio for stroke in women who admitted to using cocaine and/or amphetamine was 8.5 (95% confidence interval = 3.6-20.0). After further adjustment for potential confounders, the odds ratio in women who reported using cocaine and/or amphetamine was 7.0 (95% confidence interval = 2.8-17.9). The use of cocaine and/or amphetamine is a strong risk factor for stroke in this socioeconomically heterogeneous, insured urban population.

Adolescent↗

PubMed1996

Stroke in users of low-dose oral contraceptives.

BACKGROUND: Previous studies have linked the use of oral contraceptive agents to an increased risk of stroke, but those studies have been limited to oral contraceptives containing more estrogen than is now generally used. METHODS: In a population-based, case-control study, we identified fatal and nonfatal strokes in female members of the California Kaiser Permanente Medical Care Program and who were 15 through 44 years of age. Matched controls were randomly selected from female members who had not had strokes. Information about the use of oral contraceptives (essentially limited to low-estrogen preparations) was obtained in interviews. RESULTS: A total of 408 confirmed strokes occurred in a total of 1.1 million women during 3.6 million woman-years of observation. The incidence of stroke was thus 11.3 per 100,000 woman-years. On the basis of data from 295 women with stroke who were interviewed and their controls, the odds ratio for ischemic stroke among current users of oral contraceptives, as compared with former users and women who had never used such drugs, was 1.18 (95 percent confidence interval, 0.54 to 2.59) after adjustment for other risk factors for stroke. The adjusted odds ratio for hemorrhagic stroke was 1.14 (95 percent confidence interval, 0.60 to 2.16). With respect to the risk of hemorrhagic stroke, there was a positive interaction between the current use of oral contraceptives and smoking (odds ratio for women with both these factors, 3.64; 95 percent confidence interval, 0.95 to 13.87). CONCLUSIONS: Stroke is rare among women of childbearing age. Low-estrogen oral-contraceptive preparations do not appear to increase the risk of stroke.

Adolescent↗

PubMed1995

Agreement between self-reported early cancer detection practices and medical audits among Hispanic and non-Hispanic white health plan members in northern California.

BACKGROUND: Using the medical records of a large, prepaid health plan, our purpose was to assess the accuracy of self-reported data on cancer detection practices and to evaluate any differences in accuracy between Hispanics and non-Hispanic whites. METHODS: Data were collected on six procedures: mammography, clinical breast examination, Pap smear, sigmoidoscopy, fecal occult blood tests, and digital rectal examination. We audited the medical records of 815 randomly selected Hispanic and 483 non-Hispanic white members of the Kaiser Permanente Medical Care Program in Northern California. All responded to a telephone survey. Using a standardized form, we recorded any of the six target examinations that had been performed within 5 years of the telephone interview. We then compared the times of the most recent screening tests as reported in the telephone survey with those in the medical record. RESULTS: For the 2 years before the telephone interview, self-reports for screening tests overestimated the actual rates at which these tests were performed as documented in the medical records. Lack of agreement between self-report and medical record audits was substantial for all screening procedures except sigmoidoscopy. Hispanic members had fewer procedures done for most tests, but the differences were not statistically significant. Overestimates in self-reported screening rates did not differ substantially between Hispanics and non-Hispanic whites. CONCLUSIONS: Self-reported data on early cancer detection procedures can substantially overestimate their occurrence among both non-Hispanic white and Hispanic populations. These findings confirm earlier findings for Pap smear and affect decisions on cancer prevention procedures that rely on the accuracy of self-reported data.

Breast Neoplasms↗

PubMed1991

Risk factors for surgically treated benign prostatic hyperplasia in a prepaid health care plan.

The relationship of age, medical history, personal habits, and urologic symptoms to the incidence of surgically treated benign prostatic hyperplasia (BPH) was studied in a cohort of 16,219 men, aged forty years and over, who received multiphasic health checkups (MHCs) during 1971 and 1972 in Oakland or San Francisco while members of the Northern California Kaiser Permanente Medical Care Program, a large prepaid health care program. Follow-up was carried out for surgically treated BPH from the date of the MHC to the date of the earliest of the following: surgery for BPH (n = 1,027); incidence of prostate cancer (n = 329), bladder cancer (n = 119), or both (n = 10); other prostate surgery (n = 5); death (n = 2,525); membership termination (n = 4,235); or December 31, 1987 (n = 7,969). The mean length of follow-up was twelve years. In multivariate analysis utilizing the Cox proportional hazards model, the following characteristics were positively associated (p less than 0.05) with risk of surgically treated BPH: age, low body mass index, nonsmoking (vs. current smoking), urine pH greater than 5, history of kidney x-ray and of tuberculosis, and each of five urologic symptoms (dysuria, loss of bladder control, trouble starting urination, nocturia, slow urine stream). The risk of BPH associated with obstructive urologic symptoms decreased markedly with age. Some of these findings are consistent with those from other studies (age, nonsmoking), while others (high urine pH, history of tuberculosis) are new and should be examined in other study populations.

Adult↗