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B Harvald

Publications and source records attributed to B Harvald.

At least 19 recordsLinked to original sources
PubMed1998

[Long-term survival of patients with hypertension treated in general practice or at a specialized hypertension clinic. A 21-year observation study of 831 patients with hypertension].

This article is based on a study first published in Blood Pressure. After an initial diagnostic and therapeutic assessment at a specialized hypertension clinic, 831 patients with primary hypertension were during a 15-year period allocated to continuing managing care either by their general practitioner or by the hypertension clinic. Survival was assessed in the two groups: general practice (n = 437, 223 males, 214 females) and specialized hypertension clinic (n = 394, 208 males, 186 females). Median observation times for both groups were 11 years. There were no significant differences between the groups concerning age at entry, pretreatment clinical status, pretreatment blood pressure or treated blood pressure level before allocation. Judged by a Cox' regression model, no difference in survival between the two groups could be registered. The leading cause of death in both groups was ischemic heart disease. Our results indicate that after the initial diagnostic assessment and adjustment of treatment, managing care in a specialized hypertension clinic offers no advantage concerning survival compared to managing care in general practice.

Adult↗
PubMed1998

A population-based study of Graves' disease in Danish twins.

OBJECTIVE: The aetiology of Graves' disease (GD) is generally thought to fit a multi-factorial pattern of inheritance in which clinical disease develops on the basis of genetic susceptibility interacting with environmental and endogenous factors. In previous twin studies the probandwise concordance rates for hyperthyroidism were as high as 0.86 in monozygotic twins and 0.20 in dizygotic twins, indicating a very strong genetic influence. In these studies, however, no effort was made to distinguish between GD and non-autoimmune hyperthyroidism, and one study also included patients with simple non-toxic goitre, hampering if not invalidating any conclusions. The aim of the present study was to determine whether there is a genetic contribution in the aetiology of GD. DESIGN: Historical cohort study of pairs of same-sex twins, with information on GD being gathered by questionnaire surveys in the 1950s and 1960s. All available hospital material was sought to verify the diagnosis, which was assigned on the basis of clinical and histopathological evidence. The healthy co-twins were followed through middle age by questionnaire surveys in the 1970s and 1980s. PATIENTS: Same-sex twin individuals born between 1870-1920, included in a population-based nationwide register. A total of 118 subjects indicated hospitalization due to GD. A hospital record was available in 76 subjects. Of these, 55 (46 females and 9 males) could be classified as having GD. MEASUREMENTS: Pairwise and probandwise concordance rates for GD in monozygotic and dizygotic twin pairs. RESULTS: The probandwise concordance rates were 0.36 for monozygotic pairs and 0 for dizygotic pairs. The pairwise concordance rates were 0.22 and 0 for monozygotic and dizygotic pairs, respectively. The concordance rates were significantly (P = 0.012) higher in monozygotic than in dizygotic pairs. CONCLUSIONS: These results confirm that genetic factors play an important role in the aetiology of Graves' disease. However, they may not be as powerful as previously thought.

Adolescent↗
PubMed1997

Twenty-one-year survival of primary hypertensive patients allocated to care in general practice or in specialized hypertension clinic. An observational study of 831 hypertensive patients.

After initial diagnostic and therapeutic assessment at a specialized hypertension clinic, 831 patients with primary hypertension were during a 15-year period allocated to continuing care management either by their general practitioner or by the out-patient department of the hypertension clinic. At a given date survival was assessed in the two groups: general practice (n = 437, 233 males, 214 females) and specialized hypertension clinic (n = 394, 208 males, 186 females). Median observation time for both groups was 11 years, the longest observation time was 21 years, 8 months. There were no significant differences between the groups concerning age at entry, pretreatment clinical status, pretreatment blood pressure or treated blood pressure level before allocation. The patients in the two groups had the same access to hospitalization when needed. Judged by a Cox regression model, no difference in survival between the two groups could be registered. No differences were found between the causes of death in the two treatment groups, the main cause of death in both groups being ischaemic heart disease. Our results indicate that after initial diagnostic assessment and adjustment, the management of treatment care in a specialized hypertension clinic offers no advantage concerning survival compared to management of care in general practice.

Cause of Death↗
PubMed1996

The heritability of human longevity: a population-based study of 2872 Danish twin pairs born 1870-1900.

The aim of this study was to explore, in a large and non-censored twin cohort, the nature (i.e., additive versus non-additive) and magnitude (i.e., heritability) of genetic influences on inter-individual differences in human longevity. The sample comprised all identified and traced non-emigrant like-sex twin pairs born in Denmark during the period 1870-1900 with a zygosity diagnosis and both members of the pairs surviving the age of 15 years. A total of 2872 pairs were included. Age at death was obtained from the Danish Central Person Register, the Danish Cause-of-Death Register and various other registers. The sample was almost non-censored on the date of the last follow-up (May 1, 1994), all but 0.6% had died, leaving a total of 2872 pairs for analysis. Proportions of variance attributable to genetic and environmental factors were assessed from variance-covariance matrices using the structural equation model approach. The most parsimonious explanation of the data was provided by a model that included genetic dominance (non-additive genetic effects caused by interaction within gene loci) and non-shared environmental factors (environmental factors that are individual-specific and not shared in a family). The heritability of longevity was estimated to be 0.26 for males and 0.23 for females. The small sex-difference was caused by a greater impact of non-shared environmental factors in the females. Heritability was found to be constant over the three 10-year birth cohorts included. Thus, longevity seems to be only moderately heritable. The nature of genetic influences on longevity is probably non-additive and environmental influences non-shared. There is no evidence for an impact of shared (family) environment.

Aged↗
PubMed1996

Untangling genetic influences on smoking, body mass index and longevity: a multivariate study of 2464 Danish twins followed for 28 years.

A multivariate twin study was conducted in order to evaluate to what extent smoking, BMI and longevity are influenced by common genetic factors. The study was based on a 28-year follow-up of a sample of 2464 Danish twins who were born in the period 1890-1920 and who answered a questionnaire, including requests for information on smoking status, height and weight, in 1966. By 1994, approximately 2/3 of the sample had died. To compensate for the right-censoring, age at death was imputed for twins who were still alive by using survival analysis; all living subjects were more than 73 years old (mean 80 years, SD 5) in 1994. Proportions of covariance resulting from genetic and environmental factors in common and unique to the three traits were estimated from covariance matrices using the structural equation model approach. The study found no evidence for a substantial impact of common genetic factors on smoking, BMI and longevity. This suggests that only a small fraction of the genetic influences on longevity is mediated via a genetic influence on smoking and BMI and, furthermore, that it is unlikely that the associations between smoking and mortality and between BMI and mortality are confounded by common genetic factors.

Aged↗
PubMed1996

Sex and age specific assessment of genetic and environmental influences on body mass index in twins.

OBJECTIVE: To assess, by use of a population based twin register, if there are sex and age differences in genetic and environmental influences on inter-individual variation in BMI among middle-aged and elderly subjects. DESIGN: Twin study. SUBJECTS: 1233 like-sex Danish twin pairs (213 MZ male, 322 DZ male, 280 MZ female, 418 DZ female pairs, age: 46-76 years, BMI: 15-45 kg/m2). MEASUREMENTS: Self-reported height and weight. METHODS: Proportions of variance due to genetic and environmental factors were estimated from variance-covariance matrices using the structural equation model approach. RESULTS: The most parsimonious explanation of the data was provided by a model that included additive genetic and non-shared environmental factors with the latter fixed to be equal across sex and age. The heritability of BMI was estimated to be 0.46 for males aged 46-59 years, 0.61 for males aged 60-76 years, 0.77 for females aged 46-59 years and 0.75 for females aged 60-76 years. CONCLUSION: As in earlier studies, the present one showed a high heritability of BMI throughout adult life, with genetic influences being mainly additive and environmental influences being non-shared, without evidence for major impact of genetic dominance or shared environment. Most twin, family and adoption studies do not suggest important sex or age differences in magnitude of genetic effects, but we found that females had greater heritability than males, and that heritability in males increased by age.

Aged↗
PubMed1996

The Danish Twin Register.

BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource.

Child↗
PubMed1993

Drug related hospital admissions. Results from an intervention program.

As part of a high-intensity monitoring study of drug events as the cause of admission to departments of internal medicine, the effect of an educational intervention programme was studied. Two departments were included, one specialising in geriatrics and one that received patients by non-selected referral. The series consisted of 607 consecutive admissions studied before and 703 after the intervention. The drug events considered were adverse drug reactions and dose-related therapeutic failures, mainly due to non-compliance. A modest, statistically non-significant decrease in drug related hospital admissions (DRH) was seen, from 14% before to 13% after the intervention period. However, DRHs classified as definitely avoidable showed the significant decrease of 83%. There was no apparent relationship between the topics selected for the intervention programme and changes in the pattern of DRHs. No relationship between alterations in sales data and hospital admissions caused by a given drug could be demonstrated. A blinded external evaluation of case abstracts did not disclose any significant shift in the investigators' assessments. The intervention may have had an non-specific effect on avoidable DRHs.

Denmark↗
PubMed1993

Longevity is moderately heritable in a sample of Danish twins born 1870-1880.

The heritability of human longevity was investigated in a sample of 218 pairs of monozygotic (MZ) and 382 pairs of like-sex dizygotic (DZ) Danish twin pairs born 1870-1880. Twin similarity for age at death was significant for MZ twins but nonsignificant for DZ twins. The heritability (h2) of life span estimated from the best-fitting biometrical model was statistically significant but moderate in magnitude (h2 = .333 +/- .058). Heritability of longevity did not vary by gender, and the pattern of twin resemblance was more consistent with nonadditive as compared to additive genetic effects. In addition, evidence for a genetic association between premature and senescent deaths was observed. Although environmental factors accounted for a majority of the variance in life span, the relevant environmental factors appeared to be those that create differences rather than similarities among reared-together relatives. Findings are discussed in terms of their relevance for understanding the inheritance and evolution of human life span.

Aged↗
PubMed1992

Drug related admissions to medical wards: a population based survey.

1. In total 1999 consecutive admissions to six medical wards were subjected to a prospective high-intensity drug event monitoring scheme to assess the extent and pattern of admissions caused by adverse drug reactions (ADRs) or dose related therapeutic failures (TF), in a population-based design. The wards were sub-specialised in general medicine, geriatrics, endocrinology, cardiology, respiratory medicine and gastroenterology. 2. Considering definite, probable and possible drug events, the prevalence of drug related hospital admissions was 11.4% of which 8.4% were caused by ADRs and 3.0% by TFs. There were large inter-department differences. 3. The six classes of drugs most frequently involved in admissions caused by ADRs were anti-rheumatics and analgesics (27%), cardiovascular drugs (23%), psychotropic drugs (14%), anti-diabetics (12%), antibiotics (7%), and corticosteroids (5%). Noncompliance accounted for 66% of the TFs with diuretics and anti-asthmatics most frequently involved. 4. The pattern of drugs involved in ADRs was compared with the regional drug sales statistics. Drugs with a particularly high rate of ADR related admissions per unit dispensed were nitrofurantoin and insulin (617 and 182 admissions per 1,000,000 defined daily doses), while low rates were seen for diuretics and benzodiazepines (10 and 7 admissions per 1,000,000 defined daily doses). Confidence intervals were wide. 5. Patients who had their therapy prescribed by a hospital doctor had a slightly higher prevalence of drug events than those who were treated by a general practitioner (12.6% vs 11.8%). The reverse applied for drug events assessed as avoidable (3.3% vs 4.6%). Although these differences were not statistically significant, it may suggest general practitioners as the appropriate target for interventive measures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗