Kaiser Permanente Medical Care Program Research Articles

Plant foods, fiber, and rectal cancer

Associations between colon and rectal cancer and intakes of vegetables, other plant foods, and fiber have stimulated much debate. We examined the association between rectal cancer and plant food and fiber intakes. Data from 952 incident cases of rectal cancer were compared with data from 1205 population-based controls living in Utah or enrolled in the Kaiser Permanente Medical Care Program in northern California Rectal cancer was inversely associated with intakes of vegetables (odds ratio: 0.72; 95% CI: 0.54, 0.98), fruit (0.73; 0.53, 0.99), and whole-grain products (0.69; 0.51, 0.94), whereas a high intake of refined-grain products was directly associated with an increased risk of rectal cancer (1.42; 1.04, 1.92). Similarly, relative to low fiber intakes, high intakes of dietary fiber reduced the risk of rectal cancer (0.54; 0.37, 0.78). The reduced risk of rectal cancer associated with vegetable (0.48; 0.29, 0.80), fruit (0.63; 0.38, 1.06), and fiber (0.40; 0.22, 0.71) intakes was strongest for persons who received the diagnosis after age 65 y. A threshold effect at approximately 5 servings of vegetables/d was needed to see a reduced risk of rectal cancer. The results suggest that plant foods may be important in the etiology of rectal cancer in both men and women. Age at diagnosis appears to play an important role in the association.

Acceptance of flexible sigmoidoscopy screening for colorectal cancer

This study was conducted in the Kaiser Permanente Medical Care Program of Northern California to identify patient characteristics that explain interest in flexible sigmoidoscopy (FS) screening. A mailed screening invitation to 6837 age-eligible patients elicited responses from 49%. Efforts to reach and interview both eligible respondents and non-respondents resulted in 2728 computer-assisted telephone interviews (CATI), with 60% indicating interest in FS screening. Five components of the Integrated Behavioral Model were measured with respect to FS screening: attitude, affect, social influence, facilitators/barriers, and perceived risk of colorectal cancer. All five model components were significantly and independently associated with interest in FS, with patient attitude being the strongest predictor. Of the 32 items comprising the model components, nine items having the highest correlations with FS interest were identified as potentially important issues to address by efforts to increase interest in screening. Six of these were attitudinal beliefs. The findings from this theory-driven study provide specific targets for the design of interventions to increase FS interest and screening rates.

Chorioamnionitis and cerebral palsy in term and near-term infants.

Half of all cases of cerebral palsy (CP) occur in term infants, for whom risk factors have not been clearly defined. Recent studies suggest a possible role of chorioamnionitis. To determine whether clinical chorioamnionitis increases the risk of CP in term and near-term infants. Case-control study nested within a cohort of 231 582 singleton infants born at 36 or more weeks' gestation between January 1, 1991, and December 31, 1998, in the Kaiser Permanente Medical Care Program, a managed care organization providing care for more than 3 million residents of northern California. Case patients were identified from electronic records and confirmed by chart review by a child neurologist, and comprised all children with moderate to severe spastic or dyskinetic CP not due to postnatal brain injury or developmental abnormalities (n = 109). Controls (n = 218) were randomly selected from the study population. Association between clinical chorioamnionitis and increased risk of CP in term and near-term infants. Most CP cases had hemiparesis (40%) or quadriparesis (38%); 87% had been diagnosed by a neurologist and 83% had undergone neuroimaging. Chorioamnionitis, considered present if a treating physician made a diagnosis of chorioamnionitis or endometritis clinically, was noted in 14% of cases and 4% of controls (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.5-10.1; P =.001). Independent risk factors identified in multiple logistic regression included chorioamnionitis (OR, 4.1; 95% CI, 1.6-10.1), intrauterine growth restriction (OR, 4.0; 95% CI, 1.3-12.0), maternal black ethnicity (OR, 3.6; 95% CI, 1.4-9.3), maternal age older than 25 years (OR, 2.6; 95% CI, 1.3-5.2), and nulliparity (OR, 1.8; 95% CI, 1.0-3.0). The population-attributable fraction of chorioamnionitis for CP is 11%. Our data suggest that chorioamnionitis is an independent risk factor for CP among term and near-term infants.

Hot tub use during pregnancy and the risk of miscarriage.

To examine whether hot tub or whirlpool bath use during pregnancy increases the risk of miscarriage, the authors conducted a 1996-1998 population-based prospective cohort study at the Kaiser Permanente Medical Care Program in Oakland, California. Of 2729 eligible women, 1063 completed the interview. Miscarriage before 20 weeks of gestation was ascertained for all participants. Information on hot tub or whirlpool bath use was obtained during an in-person interview conducted early in the pregnancy. A Cox proportional hazards model was used to estimate the hazard ratio after adjustment for potential confounders. Compared with nonuse, use of a hot tub or whirlpool bath after conception was associated with a twofold increased risk of miscarriage (adjusted hazard ratio (aHR) = 2.0, 95% confidence interval: 1.3, 3.1). The risk seemed to increase with increasing frequency of use (aHR = 1.7 for less than once a week, aHR = 2.0 for once a week, and aHR = 2.7 for more than once a week) and with use during early gestation (aHR = 2.3 for initial use within the first 4 weeks of the last menstrual period and aHR = 1.5 for initial use after 4 weeks of the last menstrual period). Findings suggest an association between use of a hot tub or whirlpool bath during early pregnancy and the risk of miscarriage.

Family history and colorectal cancer: predictors of risk.

While the association between family history of colorectal cancer in first-degree relatives and risk of developing colon cancer has been well defined, the association with rectal cancer is much less clear. The purpose of this study is to define rectal cancer risk associated with family history of colorectal cancer in first-degree relatives. We also evaluate diet and lifestyle factors associated with developing colorectal cancer among participants with a positive family history. Data were available from two population-based case--control studies of colon and rectal cancer. Participants were members of the Kaiser Permanente Medical Care Program (KPMCP) or residents of the state of Utah. Cases were first primary colon cancer diagnosed between 1991 and 1994 (n = 1308 cases and 1544 controls) or rectal cancer diagnosed between 1997 and 2001 (n = 952 cases and 1205 controls). A family history of colorectal cancer in any first-degree relatives slightly increased risk of rectal cancer (OR: 1.37 95% CI: 1.02-1.85). Family history of colorectal cancer was associated with the greatest risk among those diagnosed at age 50 or younger (OR: 2.09 95% CI: 0.94-4.65 for rectal tumors; OR: 3.00 95% CI: 0.98-9.20 for distal colon tumors; and OR: 7.88 95% CI: 2.62-23.7 for proximal colon tumors). Factors significantly associated with cancer risk among those with a family history of colorectal cancer, included not having a sigmoidoscopy (OR: 2.81 95% CI: 1.86-4.24): a diet not Prudent, i.e. high in fruits, vegetables, whole grains, fish and poultry, (OR: 2.79 95% CI: 1.40-5.56); smoking cigarettes (OR: 1.68 95% CI: 1.12-2.53), and eating a Western diet, i.e. a diet high in meat, refined grains, high-fat foods, and fast foods, (OR: 2.15 95% CI: 1.06-4.35). Physical inactivity was not associated with increased cancer risk among those with a positive family history of colorectal cancer. These results confirm observations reported by others that a family history of colorectal cancer increases risk of cancer among those diagnosed at a younger age. Associations with family history are weakest for rectal cancer and strongest for proximal colonic tumors. Since several diet and lifestyle factors influence development of cancer among those with a family history of the disease, there appears to be practical approaches for individuals with a family history of colorectal cancer to reduce their cancer risk.

Gestational diabetes mellitus and lesser degrees of pregnancy hyperglycemia: association with increased risk of spontaneous preterm birth.

To investigate whether different degrees of maternal glucose intolerance are associated with the risk of spontaneous preterm birth. We performed a cohort study of 46,230 pregnancies screened by a 50-g, 1-hour oral glucose tolerance test between 24 and 28 gestation weeks at the Northern California Kaiser Permanente Medical Care Program. Spontaneous preterm birth was defined as an infant born at less than 37 gestation weeks with at least one of the following: spontaneous labor, preterm premature rupture of membranes, or incompetent cervix. Glucose tolerance status was categorized as normal screening (1-hour plasma glucose less than 140 mg/dL), abnormal screening (1-hour plasma glucose of at least 140 mg/dL with a normal diagnostic 100-g, 3-hour oral glucose tolerance test result), Carpenter-Coustan (plasma glucose measurements during the diagnostic oral glucose tolerance test met the thresholds but were lower than the National Diabetes Data Group thresholds), and gestational diabetes mellitus (GDM) by the National Diabetes Data Group criteria. One thousand nine hundred fifty-six spontaneous preterm births occurred. Age-adjusted incidences of spontaneous preterm birth were 4.0% in normal screening, 5.0% in abnormal screening, 6.7% in Carpenter-Coustan, and 6.7% in GDM. In a logistic regression model adjusted for age, race-ethnicity, preeclampsia-eclampsia-pregnancy-induced hypertension, chronic hypertension, polyhydramnios, and birth weight for gestational age, pregnancies with abnormal screening, Carpenter-Coustan, and GDM had a significantly higher risk of spontaneous preterm birth than pregnancies with normal screening (relative risk [95% confidence interval]: 1.23 [1.08, 1.41], 1.53 [1.16, 2.03], and 1.42 [1.15-1.77], respectively). The risk of spontaneous preterm birth increased with increasing levels of pregnancy glycemia. This association was independent of perinatal complications that could have triggered early delivery.

What is the best measure of maternal complications of term pregnancy: ongoing pregnancies or pregnancies delivered?

Objective The purpose of this study was to determine whether rates of hypertensive disorders of pregnancy increase beyond 37 weeks of gestation and to address how best to analyze these rates. Study design This was a retrospective cohort study of all women delivered beyond 37 weeks' gestational age from 1995 to 1999 at all Kaiser Permanente Medical Care Program delivery hospitals in Northern California. Rates of gestational hypertension, preeclampsia, and eclampsia were calculated by use of both pregnancy delivered (PD) and ongoing pregnancy (OP) as the denominator. Bivariate and multivariate analyses were conducted with use of P<.05 to indicate statistical significance. Results Among the 135,560 women in this cohort, the rates of gestational hypertension, preeclampsia, and eclampsia were the same or decreased from 37 to 43 weeks' gestation using PD, but all three increased when calculated according to OP ( P<.01). Conclusion We found that among complications of pregnancy that are diagnosed ante partum, use of a different denominator led to contradictory conclusions. When hypertensive disorders of pregnancy are analyzed, ongoing pregnancies should be used as the denominator.

Exposure to non-steroidal anti-inflammatory drugs during pregnancy and risk of miscarriage: population based cohort study

Objective To evaluate whether prenatal use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with increased risk of miscarriage.Design Population based cohort study. Prenatal use of NSAIDs, aspirin, and paracetamol (acetaminophen)...

Physical activity and colorectal cancer.

Physical activity has been inconsistently associated with rectal cancer despite the consistent association between physical activity and colon cancer. In this study, the authors evaluated the association between physical activity and rectal cancer using the same questionnaire used to evaluate the previously reported association with colon cancer. A population-based study of 952 incident cases of cancer in the rectum and rectosigmoid junction and 1,205 age- and sex-matched controls was conducted in Utah and northern California at the Kaiser Permanente Medical Care Program between 1997 and 2002. Vigorous physical activity was associated with reduced risk of rectal cancer in both men and women (odds ratio (OR) = 0.60, 95% confidence interval (CI): 0.44, 0.81 for men; OR = 0.59, 95% CI: 0.40, 0.86 for women). Among men, moderate levels of physical activity also were associated with reduced risk of rectal cancer (OR = 0.70, 95% CI: 0.51, 0.97). Participation in vigorous activity over the past 20 years conferred the greatest protection for both men and women (OR = 0.55, 95% CI: 0.39, 0.78 for men; OR = 0.44, 95% CI: 0.30, 0.67 for women). In summary, physical activity was associated with reduced risk of rectal cancer in these data. The reduced risk was similar to that previously observed for colon cancer.

Perinatal Substance Abuse Intervention in Obstetric Clinics Decreases Adverse Neonatal Outcomes

In 1990 the Kaiser Permanente Medical Care Program in northern California instituted a plan, based on obstetric clinics, to intervene actively in perinatal substance abuse. In addition to screening and early identification of any abuse problems, the program emphasizes early intervention, ongoing counseling, and case management by a clinical therapist located in the prenatal clinic, the Early Start Specialist, who is experienced in substance abuse. A retrospective cohort study was undertaken to assess this effort in 6774 mothers and their infants delivered from mid-1995 to mid-1998. Women found to be at increased risk of using alcohol, tobacco, or other agents during pregnancy were referred to the specialist who carried out an in-depth psychosocial assessment and formulated a follow-up management plan that included counseling when judged to be indicated. Study groups included 782 women who were screened, assessed, and treated (SAT), 348 who were screened and assessed (SA), 262 who were only screened (S), and 5382 control women without apparent substance abuse. Women in all the substance abuse groups began perinatal care after 13 weeks' gestation more often than did control women, but rates were significantly lower for the SAT than for the SA group. The total amount of prenatal care was highest for the SAT group. The SAT women were likelier than those in the SA group to have a positive toxicology screen while pregnant. Unadjusted rates of assisted ventilation, low birth weight, and preterm delivery were lowest in the SAT and control groups. The SA and S groups had significantly higher rates than control women for these outcomes, and the SAT group had lower rates than the SA and S groups. None of 24 neonatal deaths occurred in the SAT group, but there were no significant group differences in neonatal mortality rates. Multivariate logistic regression analyses adjusting for numerous factors (maternal age, ethnicity, number of prenatal visits, coming late to prenatal care) yielded similar results. Odds ratios for assisted ventilation, low birth weight, and preterm delivery were elevated in the SA and S groups compared with control women. Admission to neonatal intensive care was significantly more frequent for all the substance abuse groups. This experience points to the need to improve perinatal outcomes in nonacademic settings, and also the value of cooperative efforts by clinicians and mental health professionals. It seems wise to closely integrate substance abuse treatment with regular prenatal care.

Infants with bilirubin levels of 30 mg/dL or more in a large managed care organization.

To describe the incidence, etiology, treatment, and outcome of newborns with total serum bilirubin (TSB) levels >or=30 mg/dL (513 micro mol/L). Population-based case series. Eleven Northern California Kaiser Permanente Medical Care Program hospitals and 1 affiliated hospital. Eleven infants with TSB levels of >or=30 mg/dL in the first 30 days after birth, identified using computer databases from a cohort of 111,009 infants born 1995-1998. Clinical data from the birth hospitalization, rehospitalization, and outpatient visits in all infants; psychometric testing at age 5 (N = 3), neurologic examinations by child neurologists at age 5 (N = 3), or primary care providers (N = 7; mean age: 2.2 years); Parent Evaluation of Developmental Status (N = 8; mean age: 4.2 years). Maximum TSB levels of the 11 infants ranged from 30.7 to 45.5 mg/dL (525 micro mol/L to 778 micro mol/L; mean: 34.9 mg/dL [597 micro mol/L]). Four were born at 35 to 36 weeks gestation, and 7 were exclusively breastfed. Two had apparent isoimmunization; the etiology for the other 9 remained obscure, although only 4 were tested for glucose-6-phosphate dehydrogenase deficiency and 1 was bacteremic. None had acute neurologic symptoms. All received phototherapy and 5 received exchange transfusions. One infant died of sudden infant death syndrome; there was no kernicterus at autopsy. Two were lost to follow-up but were neurologically normal when last seen for checkups at 18 and 43 months. One child was receiving speech therapy at age 3. There were no significant parental concerns or abnormalities in the other children. In this setting, TSB levels >or=30 mg/dL were rare and generally unaccompanied by acute symptoms. Although we did not observe serious neurodevelopmental sequelae in this small sample, additional studies are required to quantify the known, significant risk of kernicterus in infants with very high TSB levels.

Incidence of Parkinson's disease: variation by age, gender, and race/ethnicity.

The goal of this study was to estimate the incidence of Parkinson's disease by age, gender, and ethnicity. Newly diagnosed Parkinson's disease cases in 1994-1995 were identified among members of the Kaiser Permanente Medical Care Program of Northern California, a large health maintenance organization. Each case met modified standardized criteria/Hughes diagnostic criteria as applied by a movement disorder specialist. Incidence rates per 100,000 person-years were calculated using the Kaiser Permanente membership information as the denominator and adjusted for age and/or gender using the direct method of standardization. A total of 588 newly diagnosed (incident) cases of Parkinson's disease were identified, which gave an overall annualized age- and gender-adjusted incidence rate of 13.4 per 100,000 (95% confidence interval (CI): 11.4, 15.5). The incidence rapidly increased over the age of 60 years, with only 4% of the cases being under the age of 50 years. The rate for men (19.0 per 100,000, 95% CI: 16.1, 21.8) was 91% higher than that for women (9.9 per 100,000, 95% CI: 7.6, 12.2). The age- and gender-adjusted rate per 100,000 was highest among Hispanics (16.6, 95% CI: 12.0, 21.3), followed by non-Hispanic Whites (13.6, 95% CI: 11.5, 15.7), Asians (11.3, 95% CI: 7.2, 15.3), and Blacks (10.2, 95% CI: 6.4, 14.0). These data suggest that the incidence of Parkinson's disease varies by race/ethnicity.

Complications of screening flexible sigmoidoscopy

Background & Aims: Flexible sigmoidoscopy (FS) is recommended for mass screening for colorectal cancer (CRC), yet little is known about the risk of adverse events when FS is used in general clinical practice. We aimed to determine the incidence of gastrointestinal complications and acute myocardial infarction (MI) after screening FS. Methods: Northern California Kaiser Permanente Medical Care Program members of average risk for CRC (n = 107,704) who underwent screening FS during 1994 to 1996 (109,534 FS), as part of the Colorectal Cancer Prevention (CoCaP) program. The main outcome measure was hospitalization for gastrointestinal complications or acute MI within 4 weeks of FS. Results: The mean age of subjects was 61 years, and 48.8% were female. Nongastroenterologist physicians, nurses, or physician assistants performed 72% of FS. Overall, 24 persons were hospitalized for a gastrointestinal complication. Of these, 7 were serious (2 perforations, 2 episodes of diverticulitis requiring surgery, 2 cases of bleeding requiring transfusion, and 1 episode of unexplained colitis). In multivariate models, complications were significantly more common in men than in women (odds ratio, 3.34; 95% confidence interval [CI], 1.34–10.13). MI occurred in 33 persons within 4 weeks of FS, but the incidence for this period was similar to that in the subsequent 48 weeks (rate ratio, 0.8; 95% CI, 0.6–1.2). Conclusions: The risk of serious complications after screening FS in this setting appears to be modest. Although MI occurs after FS, the risk during the 4 weeks after the procedure appears to be similar to expectations for persons of screening age.GASTROENTEROLOGY 2002;123:1786-1792

Initial treatment for prostate carcinoma in relation to comorbidity and symptoms.

Evidence suggests the type of treatment received for prostate carcinoma is associated with comorbidity, but little information is available on associations with specific comorbid disease or symptoms. The authors examined the relations between treatment and comorbidity, specific comorbid disease, and symptoms. Medical records were abstracted for 1054 male members of the Kaiser Permanente medical care program diagnosed with prostate carcinoma from 1975 to 1987. Information was obtained on demographic characteristics, comorbid conditions, symptoms, tumor stage and grade, and treatment. Logistic regression was used to determine the significant predictors of treatment (radiation vs. nonaggressive treatment and surgery vs. nonaggressive treatment). Compared to nonaggressive treatment, radiation treatment was less likely among men who had prior cancer (adjusted odds ratio [OR] 0.29, 95% confidence interval [CI] 0.09-0.90) or cerebrovascular disease (OR 0.33, 95% CI 0.13-0.83). There was a significant interaction between race and myocardial infarction (P = 0.02). Surgery, compared to nonaggressive treatment, was less common among men with a prior cancer (OR 0.21, 95% CI 0.07-0.63) or congestive heart failure (OR 0.29, 95% CI 0.09-0.90). Significant interactions were observed between race and myocardial infarction (P = 0.01), diabetes and dysuria or hematuria (P = 0.02), and para- or hemiplegia and urinary frequency or nocturia (P = 0.01). Specific symptoms and comorbidity appear to influence treatment for prostate carcinoma. More research is needed on treatment differences by race.

Effects of the September 11th attacks on urgent and emergent medical evaluations in a Northern California managed care plan

Purpose To determine whether the terrorist attacks on September 11, 2001, affected the health of persons far from the attacks, we studied rates of urgent and emergency medical evaluations among the 3 million persons enrolled in a managed care plan in Northern California. Methods Using a computerized database of all urgent care and emergency department evaluations, we monitored physician diagnoses made during the 6 weeks before and after September 11, 2001, at 16 hospitals in the Kaiser Permanente Medical Care Program. Actual rates of evaluations and diagnoses were compared with expected rates based on similar periods in 1998, 1999, and 2000. Results There were 4260 fewer urgent and emergent medical evaluations than expected during the 6 weeks beginning September 11, 2001 (−4%; 95% confidence interval [CI]: −3% to −5%; P <0.0001; N = 95,603). Emergency department visits occurred at the expected rate (−1%; 95% CI: −2% to 1%; P = 0.34), but urgent care visits were reduced (−9%; 95% CI: −8% to −11%; P <0.0001). Evaluations were particularly less frequent during the week beginning September 11 (−7%; 95% CI: −4% to −9%; P <0.0001), but a decrease persisted afterwards. Compared with expected rates, injuries ( P <0.0001) and ill-defined/symptom-related diagnoses ( P <0.0001) were less frequent, while gastrointestinal diagnoses ( P = 0.01) were more frequent, during the 6 weeks after the attacks. Total urgent and emergent evaluations were mostly unchanged on September 11; only diagnoses associated with cardiac ischemia were more frequent (+70%; 95% CI: 10% to 163%; P = 0.02). Conclusion Total urgent and emergent medical evaluations in a California managed care plan were reduced during the 6 weeks after the September 11th attacks. These results may help in allocation of resources during national disasters.

Prevalence of gestational diabetes mellitus detected by the national diabetes data group or the carpenter and coustan plasma glucose thresholds.

In 2000, the American Diabetes Association proposed the adoption of the Carpenter and Coustan criteria for diagnosis of gestational diabetes mellitus (GDM). The Carpenter and Coustan cutoffs are lower than the previously recommended National Diabetes Data Group (NDDG) values and would result in higher prevalence of GDM. Our aim is to estimate the magnitude of change in prevalence of GDM using the Carpenter and Coustan thresholds as compared with the NDDG thresholds by age and ethnicity. Cross-sectional study of 28,330 women aged 14-49 years who gave birth in 1996 and were members of the Northern California Kaiser Permanente Medical Care Program. Age, ethnicity, screening, and diagnostic test results were assessed from computerized hospitalization and laboratory systems. A total of 26,481 (94%) women were screened using a 50-g, 1-h oral glucose tolerance test, and 4,190 women underwent a diagnostic 100-g, 3-h oral glucose tolerance test after an abnormal screening. Overall, the GDM prevalence among screened women was 3.2% (95% CI 3.0-3.4) by NDDG and 4.8% (95% CI 4.5-5.1) by Carpenter and Coustan criteria, and based on either threshold, it increased with age (P < 0.001). The age-adjusted GDM prevalence by NDDG and Carpenter and Coustan criteria, respectively, was 5.0 and 7.4% in Asians, 3.9 and 5.6% in Hispanics, 3.0 and 4.0% in African-Americans, and 2.4 and 3.8% in whites. Proportional increments were larger in women aged <25 years (70%) and in whites (58%). -The prevalence of GDM increased, on average, by 50% with use of the Carpenter and Coustan thresholds. Relative increments were greater in low-risk age and ethnic groups. This information would be useful for clinical settings in predicting cost of GDM based on demographic characteristics of the population.

Prevalence of dementia in users of hormone replacement therapy as defined by prescription data.

Studies of hormone replacement therapy (HRT) and dementia and cognitive impairment show mixed results. This study assessed the prevalence of dementia and cognitive impairment in users and nonusers of HRT defined using computer-stored prescription information. The study involved 3924 women 75 years of age and older who were members of the Southern California Kaiser Permanente Medical Care Program in 1998. HRT use was determined based on prescription data for 1992-1998. Cognitive function and dementia were assessed using the Telephone Interview of Cognitive Status supplemented by the Telephone Dementia Questionnaire and medical record review. Odds ratios (ORs) for cognitive impairment/dementia showed expected associations with age, education, ethnicity, and a history of stroke or Parkinson's disease. After adjustment, the OR for cognitive impairment or dementia in HRT users compared with HRT nonusers was 0.91 (95% confidence interval 0.75-1.10). The adjusted ORs for all dementia and dementia without cause in HRT users compared with nonusers were 0.77 (95% confidence interval 0.59- 1.00) and 0.78 (0.58-1.05), respectively. Twenty percent of women with cognitive impairment or dementia who had been classified as HRT users by prescription (one prescription each year from 1992-1998) denied hormone use compared with 8.8% of women without impairment. Medical record review validated prescription information for the impaired women. The study identified an important methodologic problem in studies of HRT and cognitive impairment and dementia that depend on recalled information about drug exposure. A protective effect of HRT for cognitive impairment and dementia was neither established nor ruled out based on the prescription data.

Do protease inhibitors increase the risk for coronary heart disease in patients with HIV-1 infection?

There is continued concern about protease inhibitors (PIs) causing increased risk of coronary heart disease (CHD) in HIV-infected patients. This ongoing observational study examines CHD and myocardial infarction (MI) hospitalization rates among HIV-positive members of the Kaiser Permanente Medical Care Program of Northern California, before and after PI use, and before and after any antiretroviral therapy (ART). Also, CHD and MI hospitalization rates among HIV-infected members are compared with members not known to be HIV-positive. With 4.1 years' median total follow-up, age-adjusted CHD and MI hospitalization rates were not significantly different before versus after PIs (6.2 vs. 6.7 events per 1000 person-years); or before versus after ART (5.7 vs. 6.8). However, comparing HIV-positive and -negative members, the CHD hospitalization rate was significantly higher (6.5 vs. 3.8, p =.003), and the difference in the MI rate also was higher (4.3 vs. 2.9, p =.07). Differences between HIV-positive and -negative members in the CHD risk factors measured were mixed, and the overall clinical significance of these differences is uncertain. Our data suggest that PIs and other antiretroviral therapies do not yet increase CHD or MI hospitalizations among HIV-infected individuals; however, longer follow-up is needed. Other HIV-related mechanisms may be at work, causing increased CHD and MI risk among all HIV-infected persons.

Ethnic disparities in diabetic complications in an insured population.

Higher rates of microvascular complications have been reported for minorities. Disparate access to quality health care is a common explanation for ethnic disparities in diabetic complication rates in the US population. Examining an ethnically diverse population with uniform health care coverage may be useful. To assess ethnic disparities in the incidence of diabetic complications within a nonprofit prepaid health care organization. Longitudinal observational study conducted January 1, 1995, through December 31, 1998, at Kaiser Permanente Medical Care Program in northern California. A total of 62 432 diabetic patients, including Asians (12%), blacks (14%), Latinos (10%), and whites (64%). Incident myocardial infarction (MI), stroke, congestive heart failure (CHF), and nontraumatic lower extremity amputation (LEA), defined by primary hospitalization discharge diagnosis, procedures, or underlying cause of death; and end-stage renal disease (ESRD), defined as renal insufficiency requiring renal replacement therapy or transplantation for survival or by underlying cause of death. Patterns of ethnic differences were not consistent across complications and frequently persisted despite adjustment for a wide range of demographic, socioeconomic, behavioral, and clinical factors. Adjusted hazard ratios (relative to that of whites) were 0.56, 0.68, and 0.68 for blacks, Asians, and Latinos, respectively (P<.001), for MI; 0.76 and 0.72 for Asians and Latinos, respectively (P<.01), for stroke; 0.70 and 0.61 for Asians and Latinos, respectively (P<.01), for CHF; 0.40 for Asians (P<.001) for LEA; and 2.03, 1.85, and 1.46 for blacks, Asians, and Latinos, respectively (P<.01), for ESRD. There were no statistically significant black-white differences for stroke, CHF, or LEA and no Latino-white differences for LEA. This study confirms previous reports of elevated incidence of ESRD among ethnic minorities, despite uniform medical care coverage, and provides new evidence that rates of other complications are similar or lower relative to those of whites. The persistence of ethnic disparities after adjustment suggests a possible genetic origin, the contribution of unmeasured environmental factors, or a combination of these factors.

Daily aspirin use and prostate cancer risk in a large, multiracial cohort in the US.

To examine the relationship between daily aspirin use and risk of prostate cancer in a large, racially diverse cohort of men followed for up to 32 years. The study population included 90,100 male subscribers to the Kaiser Permanente Medical Care Program who had received one or more multiphasic health checkups between 1964 and 1973. This general health checkup included a self-completed questionnaire that requested men to record if they took more than six aspirin almost every day during the previous year. Subjects were followed for the development of prostate cancer using the local tumor registry. Cox regression was used to estimate relative risks (RR) and 95% confidence intervals (CI). A total of 2,574 men developed prostate cancer. Of these, 1617 had local stage disease and 719 had either regional or distant disease at diagnosis. A total of 2466 men (2.7%) reported taking more than six aspirin almost every day during the past year at one or more health checkups. After adjusting for birth year, education, race, and the number of health checkups. the relative risk of prostate cancer associated with this amount of aspirin use was 0.76 (95% CI 0.60-0.98). Relative risks did not differ by race and were similar for both local stage and regional or distant stage prostate cancer. Results from our large, multiracial cohort study support a modest inverse relationship between daily consumption of more than six aspirin and prostate cancer risk.