Mary B. Codd

Epidemiology of idiopathic dilated and hypertrophic cardiomyopathy. A population-based study in Olmsted County, Minnesota, 1975-1984.

Using the records linkage system of the Mayo Clinic and of the Rochester Epidemiology Project, which accesses diagnostic data on the entire population of Olmsted County, Minnesota, we identified 45 new cases of idiopathic dilated cardiomyopathy (DCM) and 19 new cases of hypertrophic cardiomyopathy (HCM) among county residents for the years 1975-1984. Overall age- and sex-adjusted incidence rates were 6.0/100,000 and 2.5/100,000 person-years, respectively. The incidence of DCM doubled from 3.9/100,000 in the first 5 years to 7.9/100,000 person-years in the last 5 years of study. The corresponding change for HCM was from 1.4 to 3.6/100,000 person-years. Age- and sex-adjusted prevalence rates as of January 1, 1985, for DCM and HCM were 36.5/100,000 and 19.7/100,000 population, respectively. The prevalence of DCM in persons less than 55 years old was 17.9/100,000, over a third of whom were New York Heart Association functional Class III or IV at diagnosis. These estimates may be of value in determining the potential use of health care resources, particularly cardiac transplantation.

Incidence and prevalence of ALS in Ireland, 1995–1997: A population-based study

Background: We conducted a prospective, population-based study of ALS in the Republic of Ireland for the 3-year period 1995 to 1997. Methods: To ensure complete case ascertainment, multiple sources of information were used, including consultant neurologists, neurophysiologists, primary care physicians, and the Irish Motor Neuron Disease Association. The El Escorial diagnostic criteria for ALS were applied to all cases enrolled on the register and each patient was regularly followed up during his or her illness. Results: Between January 1, 1995, and December 31, 1997, 231 patients were diagnosed with possible, probable, or definite ALS, including 133 men (57.6%) and 98 women (42.4%). The average annual incidence rate was 2.1 per 100,000 person-years (95% CI, 1.8 to 2.4), and 2.8 per 100,000 person-years for the population older than 15 years (95% CI, 2.4 to 3.1). The incidence rate was higher for men, being 2.5 per 100,000 person-years (95% CI, 2.0 to 2.9), than for women, at 1.8 per 100,000 person-years (95% CI, 1.5 to 2.2), and increased with age for both sexes. The median age at onset was 64.2 years for men and 67.8 years for women. On December 31, 1996, the crude prevalence was 4.7 per 100,000 of the total population (95% CI, 4.0 to 5.5), and 6.2 per 100,000 for the population older than 15 years (95% CI, 5.3 to 7.1). Adjusting to the 1996 Irish population as standard, the incidence of ALS in Ireland during the 3-year study period is the third highest reported to date. Conclusions: There was a trend toward a higher incidence of ALS in the northwestern region of Ireland, although the numbers of cases involved were small and further study is required.

The Clinical Course of Idiopathic Dilated Cardiomyopathy: A Population-based Study

OBJECTIVE To describe the prognosis of individuals with idiopathic dilated cardiomyopathy in a population-based sample and to compare this with the prognosis of patients in a previous referral center case series of idiopathic dilated cardiomyopathy. DESIGN Cohort study. SETTING Population-based in Olmsted County, Minnesota. PATIENTS Forty residents of Olmsted County, Minnesota with idiopathic dilated cardiomyopathy initially diagnosed between 1975 and 1984 who were followed through 1 July 1989 and 104 patients from a Mayo Clinic referral case series from 1960 to 1973. MEASUREMENTS Survival for the population-based cohort at 1 year and 5 years. RESULTS Survival at 1 year differed dramatically between the population-based cohort and the referral case series at 1 year (95% compared with 69%, respectively) and at 5 years (80% compared with 36%, respectively) (P less than 0.001). Long-term survival for the population-based cohort was nonetheless impaired when compared with an age- and sex-matched cohort, that is, the 1980 Minnesota white population (8-year survival: observed, 58% compared with expected, 83%; P less than 0.001). Among community patients, older age (adjusted Cox model hazard ratio for 10-year increase in age, 1.59; 95% CI, 1.08 to 2.35) and lower left ventricular ejection fraction (adjusted hazard ratio for 10% decrease, 1.90; CI, 1.04 to 3.50) were independently associated with impaired survival. CONCLUSIONS These population-based data challenge the clinical perception of the clinical course of idiopathic dilated cardiomyopathy based on referral practice prognostic studies and suggest that the clinical course of this condition may be more favorable than previously recognized.

Alcohol consumption and idiopathic dilated cardiomyopathy: a case control study.

BACKGROUND Alcohol has been implicated as a risk factor for idiopathic dilated cardiomyopathy (DCM), but a causal relation has not been established. The objective of this study was to determine the association between alcohol consumption and DCM. METHODS Questionnaires detailing average weekly intake of alcohol, total lifetime consumption, and alcohol abuse were administered in a cohort of well-defined patients with DCM and a randomly selected, population-based control group. RESULTS Significantly more of the 100 patients with DCM than the 211 members of the control group drank greater than the recommended weekly intake of alcohol (40% vs 24%; p < 0.01) and were alcohol abusers according to the CAGE questionnaire (27% vs 16%; p < 0.05). The average total lifetime consumption measured in units of alcohol was also significantly greater in cases than in the control group (31,200 vs 7,904; p < 0.01). Patients with familial DCM were not significantly more likely to consume alcohol above recommended limits or to be alcohol abusers compared with nonfamilial cases. CONCLUSIONS This study confirms previous suspicion of a causal association between alcohol and DCM, with significantly more patients than members of the control group either abusing alcohol or drinking it in excess of recommended limits.

Gender differences in the management and outcome of acute myocardial infarction in unselected patients in the thrombolytic era

This study compares the clinical features, management, and outcome in men and women from a consecutive, unselected series of patients with acute myocardial infarction (AMI) who were admitted to a university cardiac center over a 3-year period. It is a retrospective observational study of 1,059 admissions with AMI identified through the Hospital In-Patient Enquiry (HIPE) registry, validated according to Minnesota Manual criteria, and followed for a period of up to 5 years (median 36 months). Women comprised 40% of all admissions, had a higher hospital mortality (24% vs. 16%, p<0.001), and were less likely to receive thrombolysis (23% vs. 33%, p<0.01), admission to coronary care (65% vs. 77%, p<0.001), or subsequent invasive or noninvasive investigations (55% vs. 63%, p<0.01). However, women with AMI were older than men with AMI (71 vs. 65 years, p<0.001). After adjusting for age, differences that remained significant were prevalence of hypertension (odds ratio [OR] 2.12, 95% confidence intervals [CI] 1.56 to 2.88) and cigarette smoking (OR 0.47, 95% CI 0.35 to 0.65), management in coronary care (OR 0.66, 95% CI 0.49 to 0.88), and hospital mortality (OR 1.48, 95% CI 1.07 to 2.04). Excess mortality occurred predominantly in women <65 years old (18% vs. 8%, OR [multivariate] 2.35, 95% CI 1.19 to 4.56), among whom multivariate analysis demonstrated a significantly lower thrombolysis rate (OR 0.48, 95% CI 0.27 to 0.86). In this group, lack of thrombolysis independently predicted hospital mortality (OR 5.37, 95% CI 1.45 to 19.82). Female gender was not an independent predictor of mortality following AMI (OR 1.42, 95% CI 0.90 to 2.26). Thus, among unselected patients, female gender is associated with, but not an independent predictor of, reduced survival after AMI. Gender differences in mortality are greatest in younger patients, who are less likely to receive thrombolysis and in whom lack of thrombolysis is independently associated with mortality after AMI.

Late effects of paralytic poliomyelitis in Olmsted County, Minnesota

We identified a cohort of 300 individuals who had paralytic polio between 1935 and 1955. All lived in Olmsted County, Minnesota. From the 247 survivors, we selected 50 subjects for detailed historical, functional, psychological, clinical, and electrophysiologic evaluation. Sixty-four percent of these 50 survivors complained of new symptoms of muscle pain, fatigue, and weakness after a period of prolonged stability. This led to changes in lifestyle or activity in only 18%. The likelihood of expressing new complaints was not related to present age or interval since polio, and electrophysiologic testing did not distinguish between those with or without new problems. The development of new difficulties in a limb was most strongly predicted by significant paralysis of that limb at the time of the acute illness. Patients with leg weakness were twice as likely to complain of new problems compared to those with arm weakness. Elevated creatine kinase levels were present only in those with new complaints.

Comparison of interferon-γ-release assays and conventional screening tests before tumour necrosis factor-α blockade in patients with inflammatory arthritis.

Objective: To compare the performance of two interferon γ release assays (IGRAs) and conventional screening tests in patients with inflammatory arthritis undergoing screening for latent tuberculosis infection (LTBI) before treatment with anti-tumour necrosis factor α (anti-TNFα) compounds. Methods: Successive patients were subjected to conventional LTBI screening, including a tuberculin skin test (TST). The T-SPOT.TB test was performed on all patients and the QuantiFERON-TB Gold test was performed on a large subset. The results of the IGRAs were compared with the results of conventional screening tests. Results: A total 150 patients were evaluated. The majority (57.9%) had rheumatoid arthritis. Previous vaccination with Bacille Calmette–Guerin was confirmed in 82% of patients. No patient had received prior anti-TB treatment. A total of 57 patients (38.0%) had at least one positive conventional risk factor. In contrast, an unequivocally positive T-SPOT.TB test was seen in only 14/143 (9.8%). There was 98.2% agreement between the two IGRAs. Statistically significant associations were found between each of the IGRAs and both TST and risk history, but not chest x-ray (CXR). A positive IGRA result was significantly associated with increased age. TB was not reactivated in any patient during the follow-up period. Interpretation: This study suggests that IGRAs may be useful when screening for LTBI before anti-TNFα therapy in patients with immune-mediated inflammatory diseases. The observations reported here also highlight the inadequate performance of CXR as a marker of LTBI.

Hospital mortality of acute myocardial infarction in the thrombolytic era

OBJECTIVE To examine the management and outcome of an unselected consecutive series of patients admitted with acute myocardial infarction to a tertiary referral centre. DESIGN A historical cohort study over a three year period (1992–94) of consecutive unselected admissions with acute myocardial infarction identified using the HIPE (hospital inpatient enquiry) database and validated according to MONICA criteria for definite or probable acute myocardial infarction. SETTING University teaching hospital and cardiac tertiary referral centre. RESULTS 1059 patients were included. Mean age was 67 years; 60% were male and 40% female. Rates of coronary care unit (CCU) admission, thrombolysis, and predischarge angiography were 70%, 28%, and 32%, respectively. Overall in-hospital mortality was 18%. Independent predictors of hospital mortality by multivariate analysis were age, left ventricular failure, ventricular arrhythmias, cardiogenic shock, management outside CCU, and reinfarction. Hospital mortality in a small cohort from a non-tertiary referral centre was 14%, a difference largely explained by the lower mean age of these patients (64 years). Five year survival in the cohort was 50%. Only age and left ventricular failure were independent predictors of mortality at follow up. CONCLUSIONS In unselected consecutive patients the hospital mortality of acute myocardial infarction remains high (18%). Age and the occurrence of left ventricular failure are major determinants of short and long term mortality after acute myocardial infarction.

Birth Weight as a Risk Factor for Childhood Acute Lymphoblastic Leukemia

Increased birth weight previously has been reported to be associated with childhood acute leukemia although the etiologic importance of this finding remains unclear. To further assess birth weight and associated parameters as a risk factor for childhood leukemia, a case/control study was performed using children with acute lymphoblastic leukemia (ALL) born in the state of Minnesota and diagnosed since 1969. Data obtained from birth registrations of 219 cases were compared with two control groups matched on date and county of birth (group I) or year of birth (group II). No significant differences were observed in mean birth weights of cases and controls. Statistically significant associations with birth weights greater than 3800 g were identified in cases diagnosed within the first 4 years of life. No associations were found between birth weight and ALL for case children diagnosed after 4 years of age. Factors that might be associated with increased birth weight, including maternal age, birth order, length of gestation, and socioeconomic status as measured by paternal education, were not found to be associated with an increased risk for ALL. The significance of the finding of high birth weight as a risk factor for childhood ALL remains unknown but suggests that pregnancy-related events may be of importance in the etiology of ALL in young children.

The Short Form 36 (SF-36) Health Survey: normative data for the Irish population.

BackgroundGeneric measures of quality of life have a wide application in health research. They measure disease impact by comparing scores in patient groups with a healthy population. They also facilitate comparative studies between different: patient groups. The SF-36 Health Survey quantifies respondents’ perceptions of their functioning in eight dimensions of daily life.AimThe aim of this study was to set normative values for the SF-36 in the Irish population aged 18 years and over.MethodA random sample of 800 subjects was drawn from the electoral register using the RANSAM method of sampling.ResultsTwo hundred and ninety five (37%) valid questionnaires were returned for analysis. The SF-36 was found to have acceptable internal consistency and validity. Normative values for the total population are presented, in addition to results for males and females across seven age groups. Ageing was associated with a decline in the physical dimensions of health.ConclusionsThere was no evidence to suggest that there were significant differences in health status between mates and females, or between this Irish sample and the published norms for the US population.