Why patients visit their doctors: assessing the most prevalent conditions in a defined American population

OBJECTIVE

To describe the prevalence of nonacute conditions among patients seeking health care in a defined US population, emphasizing age, sex, and ethnic differences.

PATIENTS AND METHODS

The Rochester Epidemiology Project (REP) medical records linkage system was used to identify all residents of Olmsted County, Minnesota, on April 1, 2009, who had consented to review of their medical records for research (142,377 patients). We then electronically extracted all International Classification of Diseases, Ninth Revision codes noted in the records of these patients by any health care institution between January 1, 2005, and December 31, 2009. We grouped International Classification of Diseases, Ninth Revision codes into clinical classification codes and then into 47 broader disease groups associated with health-related quality of life. Age- and sex-specific prevalence was estimated by dividing the number of individuals within each group by the corresponding age- and sex-specific population. Patients within a group who had multiple codes were counted only once.

RESULTS

We included a total of 142,377 patients, 75,512 (53%) of whom were female. Skin disorders (42.7%), osteoarthritis and joint disorders (33.6%), back problems (23.9%), disorders of lipid metabolism (22.4%), and upper respiratory tract disease (22.1%, excluding asthma) were the most prevalent disease groups in this population. Ten of the 15 most prevalent disease groups were more common in women in almost all age groups, whereas disorders of lipid metabolism, hypertension, and diabetes were more common in men. Additionally, the prevalence of 7 of the 10 most common groups increased with advancing age. Prevalence also varied across ethnic groups (whites, blacks, and Asians).

CONCLUSION

Our findings suggest areas for focused research that may lead to better health care delivery and improved population health.

Comorbidity and ventricular and vascular structure and function in heart failure with preserved ejection fraction: a community-based study

BACKGROUND

Patients with heart failure and preserved ejection fraction (HFpEF) display increased adiposity and multiple comorbidities, factors that in themselves may influence cardiovascular structure and function. This has sparked debate as to whether HFpEF represents a distinct disease or an amalgamation of comorbidities. We hypothesized that fundamental cardiovascular structural and functional alterations are characteristic of HFpEF, even after accounting for body size and comorbidities.

METHODS AND RESULTS

Comorbidity-adjusted cardiovascular structural and functional parameters scaled to independently generated and age-appropriate allometric powers were compared in community-based cohorts of HFpEF patients (n=386) and age/sex-matched healthy n=193 and hypertensive, n=386 controls. Within HFpEF patients, body size and concomitant comorbidity-adjusted cardiovascular structural and functional parameters and survival were compared in those with and without individual comorbidities. Among HFpEF patients, comorbidities (obesity, anemia, diabetes mellitus, and renal dysfunction) were each associated with unique clinical, structural, functional, and prognostic profiles. However, after accounting for age, sex, body size, and comorbidities, greater concentric hypertrophy, atrial enlargement and systolic, diastolic, and vascular dysfunction were consistently observed in HFpEF compared with age/sex-matched normotensive and hypertensive.

CONCLUSIONS

Comorbidities influence ventricular-vascular properties and outcomes in HFpEF, yet fundamental disease-specific changes in cardiovascular structure and function underlie this disorder. These data support the search for mechanistically targeted therapies in this disease.

Advance directives in community patients with heart failure

BACKGROUND

Although it is recommended that all patients with heart failure (HF) have advance directives (AD) in place before the end of life is imminent, the use of AD in HF has not been well studied.

METHODS AND RESULTS

We enrolled consecutive Olmsted County residents presenting with HF from October 2007 through October 2011 into a longitudinal study. Information from AD completed before enrollment and hospitalizations in the month before death were abstracted. Among 608 patients (mean age, 74.0 years; 54.9% men; 65.3%; New York Heart Association functional class 3 or 4), 164 (27.0%) patients died after a mean follow-up of 1.8 years. At enrollment, only 249 (41.0%) patients had an AD. Although most AD appointed a proxy decision-maker (90.4%), less than half addressed wishes regarding use of cardiopulmonary resuscitation (41.4%), mechanical ventilation (38.6%), or hemodialysis (10.0%) at the end of life. The independent predictors of AD completion were older age (adjusted odds ratio [OR] per 10-year increase, 1.82; 95% confidence interval [CI], 1.51–2.20), malignancy (OR, 1.58; 95% CI, 1.05–2.37), and renal dysfunction (OR for estimated glomerular filtration rate <60 mL/min 1.55; 95% CI, 1.05–2.29). At the end of life, patients with AD specifying limits in the aggressiveness of care less frequently received mechanical ventilation (OR, 0.26; 95% CI, 0.07–0.88), with a trend toward decreased intensive care unit admission (OR, 0.45; 95% CI, 0.16–1.29).

CONCLUSIONS

Despite a high mortality rate, over half of patients with HF do not have an AD, and existing AD fail to address important end-of-life medical decisions.

Longitudinal changes in ejection fraction in heart failure patients with preserved and reduced ejection fraction

BACKGROUND

Heart failure (HF) can occur in patients with preserved (HFpEF, EF≥50%) or reduced (HFrEF, EF<50%) ejection fraction (EF), but changes in EF after HF diagnosis are not well described.

METHODS AND RESULTS

Among a community cohort of incident HF patients diagnosed from 1984 to 2009 in Olmsted County, Minnesota, we obtained all EFs assessed by echocardiography from initial HF diagnosis until death or last follow-up through March 2010. Mixed effects models fit a unique linear regression line for each person using serial EF data. Compiled results allowed estimates of the change in EF over time in HFpEF and HFrEF. Among 1233 HF patients (48.3% male, mean age 75.0 years, mean follow-up 5.1 years), 559 (45.3%) had HFpEF at diagnosis. In HFpEF, on average, EF decreased by 5.8% over 5 years (P<0.001) with greater declines in older individuals and those with coronary disease. Conversely, EF increased in HFrEF (average increase 6.9% over 5 years, P<0.001). Greater increases were noted in women, younger patients, individuals without coronary disease, and those treated with evidence-based medications. Overall, 39% of HFpEF patients had an EF<50% and 39% of HFrEF patients had an EF≥50% at some point after diagnosis. Decreases in EF over time were associated with reduced survival whereas increases in EF were associated with improved survival.

CONCLUSIONS

These data suggest that progressive contractile dysfunction may contribute to the pathophysiology of HFpEF. Prospective longitudinal studies are needed to confirm these observations and establish the mechanism and clinical relevance of decline in EF over time in HFpEF.

Future directions for cardiovascular disease comparative effectiveness research: report of a workshop sponsored by the National Heart, Lung, and Blood Institute

Comparative effectiveness research (CER) aims to provide decision makers with the evidence needed to evaluate the benefits and harms of alternative clinical management strategies. CER has become a national priority, with considerable new research funding allocated. Cardiovascular disease is a priority area for CER. This workshop report provides an overview of CER methods, with an emphasis on practical clinical trials and observational treatment comparisons. The report also details recommendations to the National Heart, Lung, and Blood Institute for a new framework for evidence development to foster cardiovascular CER, and specific studies to address 8 clinical issues identified by the Institute of Medicine as high priorities for cardiovascular CER.

Thirty-day rehospitalizations after acute myocardial infarction: a cohort study

BACKGROUND

Rehospitalization is a quality-of-care indicator, yet little is known about its occurrence and predictors after myocardial infarction (MI) in the community.

OBJECTIVE

To examine 30-day rehospitalizations after incident MI.

DESIGN

Retrospective cohort study.

SETTING

Population-based registry in Olmsted County, Minnesota.

PATIENTS

3010 patients who were hospitalized in Olmsted County with first-ever MI from 1987 to 2010 and survived to hospital discharge.

MEASUREMENTS

Diagnoses, therapies, and complications during incident and subsequent hospitalizations were identified. Manual chart review was performed to determine the cause of all rehospitalizations. The hazard ratios and cumulative incidence of 30-day rehospitalizations were determined by using Cox proportional hazards regression models.

RESULTS

Among 3010 patients (mean age, 67 years; 40.5% female) with incident MI (31.2% ST-segment elevation), 643 rehospitalizations occurred within 30 days in 561 (18.6%) patients. Overall, 30.2% of rehospitalizations were unrelated to the incident MI and 42.6% were related; the relationship was unclear in 27.2% of rehospitalizations. Angiography was performed in 153 (23.8%) rehospitalizations. Revascularization was performed in 103 (16.0%) rehospitalizations, of which 46 (44.7%) had no revascularization during the index hospitalization. After adjustment for potential confounders, diabetes, chronic obstructive pulmonary disease, anemia, higher Killip class, longer length of stay during the index hospitalization, and a complication of angiography or reperfusion or revascularization were associated with increased rehospitalization risk. The 30-day incidence of rehospitalization was 35.3% in patients who experienced a complication of angiography during the index MI hospitalization and 31.6% in those who experienced a complication of reperfusion or revascularization during the index MI hospitalization, compared with 16.8% in patients who had reperfusion or revascularization without complications.

LIMITATION

This study represents the experiences of a single community.

CONCLUSION

Comorbid conditions, longer length of stay, and complications of angiography and revascularization or reperfusion are associated with increased 30-day rehospitalization risk after MI. Many rehospitalizations seem to be unrelated to the incident MI.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Risk of cardiovascular events in patients with polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) have increased prevalence of cardiovascular (CV) risk factors. However, data on the incidence of CV events are lacking in this population. Using Rochester Epidemiology Project resources, we conducted a retrospective cohort study comparing CV events in women with PCOS with those of women without PCOS in Olmsted County, Minnesota. Between 1966 and 1988, 309 women with PCOS and 343 without PCOS were identified. Mean (SD) age at PCOS diagnosis was 25.0 (5.3) years; mean age at last follow-up was 46.7 years. Mean (SD) follow-up was 23.7 (13.7) years. Women with PCOS had a higher body mass index (29.4 kg÷m2 vs 28.3 kg÷m2; p=.01). Prevalence of type 2 diabetes mellitus and hypertension and levels of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides were similar in the two groups. We observed no increase in CV events, including myocardial infarction (adjusted hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.32 to 1.72; p=.48); coronary artery bypass graft surgery (adjusted HR 1.52; 95% CI 0.42 to 5.48; p=.52); death (adjusted HR 1.03; 95% CI, 0.29 to 3.71; p=.96); death due to CV disease (adjusted HR 5.67; 95% CI 0.51 to 63.7; p=.16); or stroke (adjusted HR 1.05; 95% CI 0.28 to 3.92; p=.94). Although women with PCOS weighed more than controls, there was no increased prevalence of other CV risk factors. Furthermore, we found no increase in CV events. While prospective studies are needed to confirm these findings, women with PCOS do not appear to have adverse CV outcomes in midlife.

Prognostic value of cardiac troponin T after myocardial infarction: a contemporary community experience

OBJECTIVE

To evaluate the role of cardiac troponin T (cTnT) in predicting death, recurrent ischemic events, and heart failure among community-dwelling persons with first myocardial infarction (MI).

PATIENTS AND METHODS

Consecutive Olmsted County, Minnesota, residents with an incident MI between November 6, 2002, and December 31, 2007, were studied (N=1177; mean age, 68 years). Maximal cTnT value was measured at a median of 1 day after MI (median, 0.52 ng/mL; interquartile range, 0.16-1.75 ng/mL) and evaluated as a prognostic factor using measures of absolute risk.

RESULTS

During a mean follow-up of 16 months, 276 deaths (23%) occurred, 341 patients (29%) experienced a recurrent ischemic event, and 326 patients (28%) experienced heart failure. A dose-response relationship was demonstrated early after MI between cTnT and the adjusted cumulative incidence of all outcomes. The multivariate-adjusted absolute risk differences (events per 100 patients) between the upper and lower cTnT tertiles at 30 days were 5.8 (95% confidence interval [CI], 1.4-10.2) for death, 5.2 (95% CI, 0.2-10.3) for recurrent ischemic event, and 6.9 (95% CI, 1.4-12.4) for heart failure. These differences were either maintained or increased at 2 years.

CONCLUSION

In the community, cTnT level predicts death and nonfatal cardiac events independently of other prognostic factors. The increased risk associated with elevated cTnT level appears shortly after MI and persists for at least 2 years.

Pulmonary pressures and death in heart failure: a community study

OBJECTIVES

The purpose of this study was to determine among community patients with heart failure (HF) whether pulmonary artery systolic pressure (PASP) assessed by Doppler echocardiography was associated with death and improved risk prediction over established factors, using the integrated discrimination improvement and net reclassification improvement.

BACKGROUND

Although several studies have focused on idiopathic pulmonary arterial hypertension, less is known about pulmonary hypertension among patients with HF, particularly about its prognostic value in the community.

METHODS

Between 2003 and 2010, Olmsted County residents with HF prospectively underwent assessment of ejection fraction, diastolic function, and PASP by Doppler echocardiography.

RESULTS

PASP was recorded in 1,049 of 1,153 patients (mean age 76 ± 13; 51% women). Median PASP was 48 mm Hg (25th to 75th percentile: 37.0 to 58.0). There were 489 deaths after a follow-up of 2.7 ± 1.9 years. There was a strong positive graded association between PASP and mortality. Increasing PASP was associated with an increased risk of death (hazard ratio [HR]: 1.45, 95% confidence interval [CI]: 1.13 to 1.85 for tertile 2; HR: 2.07, 95% CI: 1.62 to 2.64 for tertile 3 vs. tertile 1), independently of age, sex, comorbidities, ejection fraction, and diastolic function. Adding PASP to models including these clinical characteristics resulted in an increase in the c-statistic from 0.704 to 0.742 (p = 0.007), an integrated discrimination improvement gain of 4.2% (p < 0.001), and a net reclassification improvement of 14.1% (p = 0.002), indicating that PASP improved prediction of death over traditional prognostic factors. All results were similar for cardiovascular death.

CONCLUSIONS

Among community patients with HF, PASP strongly predicts death and provides incremental and clinically relevant prognostic information independently of known predictors of outcomes.

Nocturia is associated with an increased risk of coronary heart disease and death

What's known on the subject? and What does the study add? Nocturia has been associated with multiple chronic conditions, however, previous studies have been conducted only at a single time. We found that nocturia preceded the development CHD in young men. Moderate nocturia may be an early marker of CHD in young men.

OBJECTIVE

To determine whether nocturia is associated with the development of diabetes mellitus, hypertension, coronary heart disease (CHD) and occurrence of death.

MATERIALS AND METHODS

We studied data obtained from a retrospective cohort of randomly selected men, aged 40-79 years in 1990, from Olmsted County, MN, USA. Moderate nocturia was defined as waking to urinate ≥2 times per night. Men were followed every 2 years through repeated questionnaires and community medical records to assess development of diabetes mellitus and hypertension, and occurrence of death. CHD was ascertained through ongoing surveillance of heart disease in Olmsted County. Cox proportional hazard models were used to estimate associations between baseline nocturia and each of the outcomes.

RESULTS

A total of 2447 men were followed for a median of 17.1 years (25th and 75th percentiles: 15.0, 17.4 years). Moderate nocturia was not significantly associated with the later development of diabetes mellitus or hypertension in this study. Younger men (<60 years of age) with moderate nocturia were more likely to develop CHD later in life than younger men without nocturia (hazard ratio [HR]: 1.68; 95% confidence interval [CI]: 1.13, 2.49). This association was no longer significant when adjusted for age, body mass index (BMI) and urological medications (HR: 1.36; 95% CI: 0.87, 2.12). Older men (≥60 years of age) with moderate nocturia were more likely to die than older men without moderate nocturia, even after adjusting for age, BMI, urological medications and CHD (HR: 1.48; 95% CI: 1.15, 1.91).

CONCLUSION

Nocturia may be a marker for increased risk of CHD in younger men, and death in older men.

Association of TNFSF8 polymorphisms with peripheral neutrophil count

OBJECTIVE

To investigate the association between 347 single-nucleotide polymorphisms within candidate genes of the tumor necrosis factor, interleukin 1 and interleukin 6 families with neutrophil count.

PATIENTS AND METHODS

Four hundred cases with heart failure after myocardial infarction (MI) were matched by age, sex, and date of incident MI to 694 controls (MI without post-MI heart failure). Both genotypes and neutrophil count at admission for incident MI were available in 314 cases and 515 controls.

RESULTS

We found significant associations between the TNFSF8 poly morphisms rs927374 (P=5.1 x 10(-5)) and rs2295800 (P=1.3 x 10(-4)) and neutrophil count; these single-nucleotide polymorphisms are in high linkage disequilibrium (r(2)=0.97). Associations persisted after controlling for clinical characteristics and were unchanged after adjusting for case-control status. For rs927374, the neutrophil count of GG homozygotes (7.6±5.1) was 16% lower than that of CC homozygotes (9.0±5.2).

CONCLUSION

The TNFSF8 polymorphisms rs927374 and rs2295800 were associated with neutrophil count. This finding suggests that post-MI inflammatory response is genetically modulated.

Associations of preexisting depression and anxiety with hospitalization in patients with cardiovascular disease

OBJECTIVE

To determine the risk of hospitalization and death in relation to preexisting depression and anxiety among patients with cardiovascular disease (CVD).

PATIENTS AND METHODS

The cohort consisted of 799 Olmsted County, MN, residents diagnosed with CVD (myocardial infarction or heart failure) from January 1, 1979, to December 31, 2009, who completed a Minnesota Multiphasic Personality Inventory (MMPI) prior to their event. The MMPI was used to identify depression and anxiety, and participants were followed up for hospitalizations and death during an average of 6.2 years.

RESULTS

Depression and anxiety were identified in 282 (35%) and 210 (26%) participants, respectively. After adjustment, depression and anxiety were independently associated with a 28% (95% confidence interval [CI], 8%-51%) and 26% (95% CI, 3%-53%) increased risk of being hospitalized, respectively. Depression also conferred an increased risk of all-cause mortality of similar magnitude, whereas the hazard ratio for anxiety was not statistically significant. The combined occurrence of depression and anxiety led to a 35% (95% CI, 8%-71%) increase in the risk of hospitalizations.

CONCLUSION

Among patients with CVD, both preexisting depression and anxiety, occurring on average 17 years before the CVD event, independently predict hospitalizations. In addition, the 2 conditions may act synergistically on increasing health care utilization in patients with CVD.

Atrial fibrillation and mortality in heart failure: a community study

BACKGROUND

Heart failure (HF) and atrial fibrillation (AF) share common risk factors and often coexist. The combination of HF and AF may carry a worse prognosis than either condition alone; however, the magnitude of this risk remains controversial and it is not known whether the timing of AF influences the risk of death.

METHODS AND RESULTS

We determined the risk of all-cause mortality in relation to the presence of AF prior to or after HF diagnosis in a community-based cohort of persons diagnosed as having HF between 1983 and 2006. Of 1664 individuals with HF, 553 had a history of AF and 384 developed AF after HF. During a median follow-up of 4.0 years, 450 deaths occurred among persons with prior AF, 314 among those with AF after HF, and 572 among patients without AF. In fully adjusted models, compared with patients without AF, those with AF prior to HF had a 29% increased risk of death, whereas those who developed AF after HF exhibited >2-fold increased risk of death.

CONCLUSIONS

In the community, AF is frequent in the setting of HF and is associated with a large excess risk of death. The magnitude of this excess risk differs markedly according to the timing of AF, with AF developing after HF conferring the largest increased risk of death compared with HF patients without AF.

Troponin T levels and infarct size by SPECT myocardial perfusion imaging

OBJECTIVES

To evaluate the relationship between serial cardiac troponin T (cTnT) levels with infarct size and left ventricular ejection fraction by gated single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) in patients with acute myocardial infarction (AMI).

BACKGROUND

Current guidelines recommend the use of cTnT as the biomarker of choice for the diagnosis of AMI. Data relating cTnT to SPECT-MPI in patients with AMI are limited.

METHODS

A subset of patients with their first AMI participating in a community-based cohort of AMI in Olmsted County, Minnesota, were prospectively studied. Serial cTnT levels were evaluated at presentation, <12 h and 1, 2, and 3 days after onset of pain. Peak cTnT was defined as the maximum cTnT value.

RESULTS

A total of 121 patients (age, 61 ± 13 years; 31% women) with AMI underwent gated SPECT-MPI at a median (25th percentile, 75th percentile) of 10 (5, 15) days post-AMI. The type of infarct was non-ST-segment elevation myocardial infarction in 61%, and 13% were anterior in location. The median infarct size was 1% (0%, 11%) and the median gated left ventricular ejection fraction was 54% (47%, 60%). Fifty-nine patients (49% of the population) had no measurable infarction by SPECT-MPI. Independent predictors of measurable SPECT-MPI infarct size included cTnT at days 1, 2, and 3 and peak cTnT, but not at presentation or <12 h. In receiver-operator characteristic analysis, the area under the curve was highest at day 3. Receiver-operator characteristic analysis demonstrated a cutoff of 1.5 ng/ml for peak cTnT for the detection of measurable infarct size.

CONCLUSIONS

In a community-based cohort of patients with their first AMI, independent predictors of measurable SPECT-MPI infarct size included cTnT at days 1, 2, and 3 and peak cTnT. In contrast, cTnT level at presentation and <12 h was not an independent predictor of myocardial infarction size as assessed by SPECT-MPI. Receiver-operator characteristic analysis demonstrated a cutoff value peak cTnT of 1.5 ng/ml for the detection of measurable infarct.

Highlights from the third annual Mayo Clinic conference on systems engineering and operations research in health care

In August 2010, the Third Annual Mayo Clinic Conference on Systems Engineering and Operations Research in Health Care was held. The continuing mission of the conference is to gather a multidisciplinary group of systems engineers, clinicians, administrators, and academic professors to discuss the translation of systems engineering methods to more effective health care delivery. Education, research, and practice were enhanced via a mix of formal presentations, tutorials, and informal gatherings of participants with diverse backgrounds. Although the conference promotes a diversity of perspectives and methods, participants are united in their desire to find ways in which systems engineering can transform health care, especially in the context of health care reform and other significant changes affecting the delivery of health care.

Association between myocardial infarction and fractures: an emerging phenomenon

BACKGROUND

Data on the association between myocardial infarction (MI) and fractures are scarce. Recent changes in the epidemiology of MI justify exploring this relationship. We evaluated whether MI constitutes a risk factor for osteoporotic fracture and examined secular trends in this association.

METHODS AND RESULTS

Consecutive Olmsted County, Minnesota, residents with incident MI diagnosed in 1979 to 2006 and community control subjects individually matched (1:1) to cases on age, sex, and year of onset (n=6642) were followed up through 2009. Outcome measures were time to osteoporotic fracture, overall and by anatomic site, and death. Fracture incidence rates were stable in controls but increased markedly over time among MI cases. Accordingly, although an overall excess of fracture risk after MI was observed (adjusted hazard ratio, 1.32; 95% confidence interval, 1.12 to 1.56), substantial temporal variations were noted (1979 to 1989: hazard ratio, 0.81; 95% confidence interval, 0.58 to 1.12; 1990 to 1999: hazard ratio, 1.47; 95% confidence interval, 1.10 to 1.96; 2000 to 2006: hazard ratio, 1.73; 95% confidence interval, 1.32 to 2.27; P for trend <0.001). Trends were similar regardless of age, sex or fracture site. Conversely, the overall hazard ratio for death in MI cases versus controls did not change materially despite a continuous decline in 30-day case fatality rate (12.5% in 1979 to 1989; 6.7% in 2000 to 2006). Observed changes in the baseline prevalence of cardiovascular risk factors, MI characteristics, and comorbidities did not fully account for the trends in fracture risk.

CONCLUSIONS

Over the past decades, the association between MI and osteoporotic fractures increased steadily. The trend is consistent with the displacement of post-MI outcomes toward noncardiovascular events, highlighting the need for comprehensive prevention strategies to accommodate the changing epidemiology of MI.