Steven J. Jacobsen

Age-Specific Reference Ranges for Serum Prostate-Specific Antigen in Black Men

BACKGROUND The detection of prostate cancer by screening for prostate-specific antigen (PSA) in serum is improved when age-specific reference ranges are used, but these ranges have been derived from white populations. We determined the distribution of PSA and age-specific reference ranges in black men both with and without prostate cancer. METHODS From January 1991 through May 1995, we measured serum PSA in 3475 men with no clinical evidence of prostate cancer (1802 white and 1673 black) and 1783 men with prostate cancer (1372 white and 411 black). We studied the data as a function of age and race to determine the usefulness of measuring PSA in diagnosing prostate cancer. RESULTS Serum PSA concentrations in black men (geometric mean in controls, 1.48 ng per milliliter; in patients, 7.46) were significantly higher than those in white men (geometric mean in controls, 1.33 ng per milliliter; in patients, 6.28). The values in the controls correlated directly with age. The area under the receiver-operating-characteristic curve was 0.91 for blacks and 0.94 for whites. If traditional age-specific reference ranges were used in screening black men, with the test specificity kept at 95 percent, 41 percent of cases of prostate cancer would be missed. For the test to have 95 percent sensitivity among black men, the following normal reference ranges should be used: for men in their 40s, 0 to 2.0 ng of PSA per milliliter (test specificity, 93 percent); for men in their 50s, 0 to 4.0 ng per milliliter (specificity, 88 percent); for men in their 60s, 0 to 4.5 ng per milliliter (specificity, 81 percent); and for men in their 70s, 0 to 5.5 ng per milliliter (specificity, 78 percent). CONCLUSIONS Serum PSA concentrations can be used to discriminate between men with prostate cancer and those without it among both blacks and whites. Over 40 percent of cases of prostate cancer in black men would not be detected by tests using traditional age-specific reference ranges, which maintain specificity at 95 percent. In this high-risk population, the alternative approach--maintaining sensitivity at 95 percent--may be used with acceptable decrements in specificity.

A Population-Based, Longitudinal Study of Erectile Dysfunction and Future Coronary Artery Disease

OBJECTIVE To assess the association between erectile dysfunction (ED) and the long-term risk of coronary artery disease (CAD) and the role of age as a modifier of this association. PARTICIPANTS AND METHODS From January 1, 1996, to December 31, 2005, we biennially screened a random sample of 1402 community-dwelling men with regular sexual partners and without known CAD for the presence of ED. Incidence densities of CAD were calculated after age stratification and adjusted for potential confounders by time-dependent Cox proportional hazards models. RESULTS The prevalence of ED was 2% for men aged 40 to 49 years, 6% for men aged 50 to 59 years, 17% for men aged 60 to 69 years, and 39% for men aged 70 years or older. The CAD incidence densities per 1000 person-years for men without ED in each age group were 0.94 (40-49 years), 5.09 (50-59 years), 10.72 (60-69 years), and 23.30 (> or =70 years). For men with ED, the incidence densities of CAD for each age group were 48.52 (40-49 years), 27.15 (50-59 years), 23.97 (60-69 years), and 29.63 (> or =70 years). CONCLUSION ED and CAD may be differing manifestations of a common underlying vascular pathology. When ED occurs in a younger man, it is associated with a marked increase in the risk of future cardiac events, whereas in older men, ED appears to be of little prognostic importance. Young men with ED may be ideal candidates for cardiovascular risk factor screening and medical intervention.

Do cardiovascular risk factors confer the same risk for cardiovascular outcomes in rheumatoid arthritis patients as in non-rheumatoid arthritis patients?

Objective: To compare the frequency of traditional cardiovascular (CV) risk factors in rheumatoid arthritis (RA) compared to non-RA subjects, and examine their impact on the risk of developing selected CV events (myocardial infarction (MI), heart failure (HF) and CV death) in these two groups. Methods: We examined a population-based incidence cohort of subjects with RA (defined according to the 1987 American College of Rheumatology criteria), and an age- and sex-matched non-RA cohort. All subjects were followed longitudinally through their complete community medical records, until death, migration, or 1 January 2001. Clinical CV risk factors and outcomes were defined using validated criteria. The χ2 test was used to compare the frequency of each CV risk factor at baseline. Person-years methods were used to estimate the rate of occurrence of each CV risk factor during follow-up. Cox models were used to examine the influence of CV risk factors on the development of CV outcomes. Results: A total of 603 RA and 603 non-RA subjects (73% female; mean age 58 years) were followed for a mean of 15 and 17 years (total: 8842 and 10 101 person-years), respectively. At baseline, RA subjects were significantly more likely to be former or current smokers when compared to non-RA subjects (p<0.001). Male gender, smoking, and personal cardiac history had weaker associations with CV events among RA subjects, compared to non-RA subjects. There was no significant difference between RA and non-RA subjects in the risk imparted with respect to the other CV risk factors (ie, family cardiac history, hypertension, dyslipidaemia, body mass index, or diabetes mellitus). Conclusion: While some traditional CV risk factors imparted similar risk among RA compared with non-RA subjects, others (ie, male gender, smoking and personal cardiac history) imparted significantly less risk for the development of CV disease. These differences in the overall impact of traditional CV risk factors suggest that strategies to prevent CV disease and mortality focused solely on controlling traditional CV risk factors may be relatively less beneficial in RA subjects than in the general population. Further research is needed to determine optimal approaches to reducing CV morbidity and mortality in persons with RA.

Trends in Incidence, Severity, and Outcome of Hospitalized Myocardial Infarction

Background— In 2000, the definition of myocardial infarction (MI) changed to rely on troponin rather than creatine kinase (CK) and its MB fraction (CK-MB). The implications of this change on trends in MI incidence and outcome are not defined. Methods and Results— This was a community study of 2816 patients hospitalized with incident MI from 1987 to 2006 in Olmsted County, Minnesota, with prospective measurements of troponin and CK-MB from August 2000 forward. Outcomes were MI incidence, severity, and survival. After troponin was introduced, 278 (25%) of 1127 incident MIs met only troponin-based criteria. When cases meeting only troponin criteria were included, incidence did not change between 1987 and 2006. When restricted to cases defined by CK/CK-MB, the incidence of MI declined by 20%. The incidence of non–ST-segment elevation MI increased markedly by relying on troponin, whereas that of ST-segment elevation MI declined regardless of troponin. The age- and sex-adjusted hazard ratio of death within 30 days for an infarction occurring in 2006 (compared with 1987) was 0.44 (95% confidence interval, 0.30 to 0.64). Among 30-day survivors, survival did not improve, but causes of death shifted from cardiovascular to noncardiovascular (P=0.001). Trends in long-term survival among 30-day survivors were similar regardless of troponin. Conclusions— Over the last 2 decades, a substantial change in the epidemiology of MI occurred that was only partially mediated by the introduction of troponin. Non–ST-segment elevation MIs now constitute the majority of MIs. Although the 30-day case fatality improved markedly, long-term survival did not change, and the cause of death shifted from cardiovascular to noncardiovascular.

The Vaccine Safety Datalink: A Model for Monitoring Immunization Safety

The Vaccine Safety Datalink (VSD) project is a collaborative project between the Centers for Disease Control and Prevention and 8 managed care organizations (MCOs) in the United States. Established in 1990 to conduct postmarketing evaluations of vaccine safety, the project has created an infrastructure that allows for high-quality research and surveillance. The 8 participating MCOs comprise a large population of 8.8 million members annually (3% of the US population), which enables researchers to conduct studies that assess adverse events after immunization. Each MCO prepares computerized data files by using a standardized data dictionary containing demographic and medical information on its members, such as age and gender, health plan enrollment, vaccinations, hospitalizations, outpatient clinic visits, emergency department visits, urgent care visits, and mortality data, as well as additional birth information (eg, birth weight) when available. Other information sources, such as medical chart review, member surveys, and pharmacy, laboratory, and radiology data, are often used in VSD studies to validate outcomes and vaccination data. Since 2000, the VSD has undergone significant changes including an increase in the number of participating MCOs and enrolled population, changes in data-collection procedures, the creation of near real-time data files, and the development of near real-time postmarketing surveillance for newly licensed vaccines or changes in vaccine recommendations. Recognized as an important resource in vaccine safety, the VSD is working toward increasing transparency through data-sharing and external input. With its recent enhancements, the VSD provides scientific expertise, continues to develop innovative approaches for vaccine-safety research, and may serve as a model for other patient safety collaborative research projects.

Sociodemographic characteristics of members of a large, integrated health care system: comparison with US Census Bureau data.

BACKGROUND Data from the memberships of large, integrated health care systems can be valuable for clinical, epidemiologic, and health services research, but a potential selection bias may threaten the inference to the population of interest. METHODS We reviewed administrative records of members of Kaiser Permanente Southern California (KPSC) in 2000 and 2010, and we compared their sociodemographic characteristics with those of the underlying population in the coverage area on the basis of US Census Bureau data. RESULTS We identified 3,328,579 KPSC members in 2000 and 3,357,959 KPSC members in 2010, representing approximately 16% of the population in the coverage area. The distribution of sex and age of KPSC members appeared to be similar to the census reference population in 2000 and 2010 except with a slightly higher proportion of 40 to 64 year olds. The proportion of Hispanics/Latinos was comparable between KPSC and the census reference population (37.5% vs 38.2%, respectively, in 2000 and 45.2% vs 43.3% in 2010). However, KPSC members included more blacks (14.9% vs 7.0% in 2000 and 10.8% vs 6.5% in 2010). Neighborhood educational levels and neighborhood household incomes were generally similar between KPSC members and the census reference population, but with a marginal underrepresentation of individuals with extremely low income and high education. CONCLUSIONS The membership of KPSC reflects the socioeconomic diversity of the Southern California census population, suggesting that findings from this setting may provide valid inference for clinical, epidemiologic, and health services research.

Long-term school outcomes for children with attention-deficit/hyperactivity disorder: a population-based perspective.

Objective: The purpose of this study was to compare long-term school outcomes (academic achievement in reading, absenteeism, grade retention, and school dropout) for children with attention-deficit/hyperactivity disorder (AD/HD) versus those without AD/HD. Methods: Subjects included 370 children with research-identified AD/HD from a 1976–1982 population-based birth cohort (N = 5718) and 740 non-AD/HD control subjects from the same birth cohort, matched by gender and age. All subjects were retrospectively followed from birth until a median age of 18.4 years (AD/HD cases) or 18.3 years (non-AD/HD controls). The complete school record for each subject was reviewed to obtain information on reading achievement (last available California Achievement Test reading score), absenteeism (number/percentage of school days absent at each grade level), grade retention (having to repeat an entire grade in the subsequent school year), and school dropout (failure to graduate from high school). Results: Median reading achievement scores at age 12.8 years (expressed as a national percentile) were significantly different for AD/HD cases and non-AD/HD controls (45 vs 73). Results were similar for both boys and girls with AD/HD. Median percentage of days absent was statistically significantly higher for children with AD/HD versus those without AD/HD, although the difference was relatively small in absolute number of days absent. Subjects with AD/HD were three times more likely to be retained a grade. Similarly, subjects with AD/HD were 2.7 times more likely to drop out before high school graduation (22.9%) than non-AD/HD controls (10.0%). Conclusions: The results of this population-based study clearly demonstrate the association between AD/HD and poor long-term school outcomes.

Clinical study: obesity, diabetes, and heart diseaseCoronary atherosclerosis in diabetes mellitus: A population-based autopsy study☆

OBJECTIVES The study was conducted to test the hypothesis that the prevalence of coronary atherosclerosis is greater among diabetic than among nondiabetic individuals and is similar for diabetic individuals without clinical coronary artery disease (CAD) and nondiabetics with clinical CAD. BACKGROUND Persons with diabetes but without clinical CAD encounter cardiovascular mortality similar to nondiabetic individuals with clinical CAD. This excess mortality is not fully explained. We examined the association between diabetes and coronary atherosclerosis in a geographically defined autopsied population, while capitalizing on the autopsy rate and medical record linkage system available via the Rochester Epidemiology Project, which allows rigorous ascertainment of coronary atherosclerosis, clinical CAD, and diabetes. METHODS Using two measures, namely a global coronary score and high-grade stenoses, the prevalence of atherosclerosis was analyzed in a cohort of autopsied residents of Rochester, Minnesota, age 30 years or older at death, while stratifying on diabetes, clinical CAD diagnosis, age, and gender. RESULTS In this cohort, diabetes was associated with a higher prevalence of atherosclerosis. Among diabetic decedents without clinical CAD, almost three-fourths had high-grade coronary atherosclerosis and more than half had multivessel disease. Without diabetes, women had less atherosclerosis than men, but this female advantage was lost with diabetes. Among those without clinical CAD, diabetes was associated with a global coronary disease burden and a prevalence of high-grade atherosclerosis similar to that observed among nondiabetic subjects with clinical CAD. CONCLUSIONS These findings provide mechanistic insights into the excess risk of clinical CAD among diabetic individuals, thereby supporting the need for aggressive prevention of atherosclerosis in all diabetic individuals, irrespective of clinical CAD symptoms.

Math learning disorder: incidence in a population-based birth cohort, 1976-82, Rochester, Minn.

OBJECTIVE To report the incidence of math learning disorder (Math LD) among school-aged children, overall and by gender. To compare incidence estimates obtained by using three different methods to identify Math LD cases. To assess the extent to which children manifest Math LD alone, versus Math LD with comorbid reading disorder. METHODS This is a population-based, retrospective, birth cohort study. Subjects included all children born 1976-82 who remained in Rochester, Minn after age 5 (N = 5718). Using records from all public and private schools, medical facilities, and private tutorial services, all individually administered intelligence quotient and achievement tests and extensive medical, educational, and socioeconomic information were abstracted. Math LD was established using research criteria based on 3 formulas (regression-based discrepancy, nonregression-based discrepancy, low achievement). RESULTS Cumulative incidence rates of Math LD by age 19 years varied from 5.9% to 13.8% according to the formula used. Boys were more likely to be affected than girls, with relative risk ratios from 1.6 to 2.2 depending on the formula applied. Many children with Math LD (35% to 56.7%, depending on the formula used to define Math LD) did not have a comorbid reading disorder. CONCLUSIONS These results, from a community-based birth cohort, suggest that Math LD is common among schoolchildren, and is significantly more frequent among boys than girls, regardless of definition. Many children with Math LD do not have an associated reading disorder.

Herpes zoster vaccine in older adults and the risk of subsequent herpes zoster disease.

CONTEXT Approximately 1 million episodes of herpes zoster occur annually in the United States. Although prelicensure data provided evidence that herpes zoster vaccine works in a select study population under idealized circumstances, the vaccine needs to be evaluated in field conditions. OBJECTIVE To evaluate risk of herpes zoster after receipt of herpes zoster vaccine among individuals in general practice settings. DESIGN, SETTING, AND PARTICIPANTS A retrospective cohort study from January 1, 2007, through December 31, 2009, of individuals enrolled in the Kaiser Permanente Southern California health plan. Participants were immunocompetent community-dwelling adults aged 60 years or older. The 75,761 members in the vaccinated cohort were age matched (1:3) to 227,283 unvaccinated members. MAIN OUTCOME MEASURE Incidence of herpes zoster. RESULTS Herpes zoster vaccine recipients were more likely to be white, women, with more outpatient visits, and fewer chronic diseases. The number of herpes zoster cases among vaccinated individuals was 828 in 130,415 person-years (6.4 per 1000 person-years; 95% confidence interval [CI], 5.9-6.8), and for unvaccinated individuals it was 4606 in 355,659 person-years (13.0 per 1000 person-years; 95% CI, 12.6-13.3). In adjusted analysis, vaccination was associated with a reduced risk of herpes zoster (hazard ratio [HR], 0.45; 95% CI, 0.42-0.48); this reduction occurred in all age strata and among individuals with chronic diseases. Risk of herpes zoster differed by vaccination status to a greater magnitude than the risk of unrelated acute medical conditions, suggesting results for herpes zoster were not due to bias. Ophthalmic herpes zoster (HR, 0.37; 95% CI, 0.23-0.61) and hospitalizations coded as herpes zoster (HR, 0.35; 95% CI, 0.24-0.51) were less likely among vaccine recipients. CONCLUSIONS Among immunocompetent community-dwelling adults aged 60 years or older, receipt of the herpes zoster vaccine was associated with a lower incidence of herpes zoster. The risk was reduced among all age strata and among individuals with chronic diseases.