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P K Andersen

Publications and source records attributed to P K Andersen.

154 records · Page 9Linked to original sources
PubMed1978

[A new safe system for the prevention of peroperative hypothermia (author's transl)].

On the basis of our experiences and data from the literature concerning thermal injury by warming blankets in anaesthetized patients, a new and safe system for the maintenance of body temperature during the operation is described. The following advantages are emphasized: 1. Adjustable double-thermostat with audible alarm. 2. Easy-to-read control thermometer of water bath. 3. Thermal blanket water temperature cannot rise above 43 degrees C.

Body Temperature↗
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Risk factors for parvovirus B19 infection in pregnancy.

CONTEXT: Parvovirus B19 infection during pregnancy has been associated with fetal death. However, the incidence of and risk factors for infection in pregnant women have not been well studied. OBJECTIVES: To estimate a pregnant woman's risk of infection with parvovirus B19 in epidemic and endemic situations and to study risk factors for infection. DESIGN: Population-based cohort study conducted between November 1992 and June 1994. SETTING: Three regions in Denmark. PARTICIPANTS: A total of 30946 pregnant women from a consecutive and population-based screening. MAIN OUTCOME MEASURES: Specific IgG antibodies in serum samples obtained in the first trimester of pregnancy and from the newborn infant to assess past infection and seroconversion. Information on family structure, educational background, socioeconomic status, and pregnancy outcome was obtained from national registers. RESULTS: Based on 30 946 serum samples, 65.0% of pregnant women had evidence of past infection. Annual seroconversion rates among susceptible women during endemic and epidemic periods were 1.5% (95% confidence interval [CI], 0.2%-1.9%) and 13.0% (95% CI, 8.7%-23.1 %), respectively. Baseline seropositivity was significantly correlated with increasing number of siblings, having a sibling of the same age, number of own children, and occupational exposure to children. Risk of acute infection increased with the number of children in the household as follows: 0 children odds ratio (OR), 1 (reference); 1 child OR, 3.17 (95% CI, 2.24-4.49); 2 children OR, 5.47 (95% CI, 3.55-8.45); 3 or more children OR, 7.54 (95% CI, 3.80-14.94). Having children aged 6 to 7 years resulted in the highest rate of seroconversion among mothers (6.8%; OR, 4.07; 95% CI, 1.89-8.73). Compared with other pregnant women, nursery school teachers had a 3-fold increased risk of acute infection (OR, 3.09; 95% CI, 1.62-5.89). Population-attributable risk of seroconversion was 55.4% for number of own children and 6.0% for occupational exposure. CONCLUSIONS: The risk of infection is high for susceptible pregnant women during epidemics and associated with the level of contact with children. Nursery school teachers have the highest occupational risk, but most infections seem to be the result of exposure to the woman's own children.

Acute Disease↗
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The role of frailty models and accelerated failure time models in describing heterogeneity due to omitted covariates.

In survival analysis, deviations from proportional hazards may sometimes be explained by unaccounted random heterogeneity, or frailty. This paper recalls the literature on omitted covariates in survival analysis and shows in a case study how unstably frailty models might behave when asked to account for unobserved heterogeneity in standard survival analysis with no replications per heterogeneity unit. Accelerated failure time modelling seems to avoid these difficulties and also to yield easily interpretable results. We propose that it would be advantageous to upgrade the accelerated failure time approach alongside the hazard modelling approach to survival analysis.

Algorithms↗
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Prognostic factors in cirrhosis identified by Cox's regression model.

In a controlled clinical trial in 488 patients with chronic liver disease treated with prednisone or placebo, survival data were analyzed using Cox's proportional hazards model. A total of 162 variables were screened separately for prognostic and/or therapeutic effect by log-rank analyses, whereby 46 clinical, biochemical, serological, and histological variables were isolated. Another five variables traditionally found to be important in patients with liver disease were included. After extensively checking the assumptions of the model, the 51 variables were, by a step-wise procedure, reduced to a final model. It comprised, besides a treatment indicator, 12 variables with significant (p less than 0.05) prognostic or therapeutic effect. The following eight variables had a significant prognostic effect: sex, age, prothrombin, acetylcholinesterase, eosinophil leucocytes in liver parenchyma, liver cell necrosis, inflammation in liver connective tissue, and efferent veins in parenchymal nodules. A prognostic index based on the final model is formed allowing calculation of 5 years survival probability. The usefulness of the prognostic index was tested by a cross-validation method, and no statistical significant difference was found between the estimated and observed survivorship functions.

Adult↗
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Prognostic value of Child-Turcotte criteria in medically treated cirrhosis.

The Child- Turcotte criteria (CTC) (based on serum bilirubin and albumin, ascites, neurological disorder and nutrition) are established prognostic factors in patients with cirrhosis having portacaval shunt surgery. The objective of this study was to evaluate the prognostic value of CTC in conservatively treated cirrhosis. Patients (n = 245) with histologically verified cirrhosis from a control group of a controlled clinical trial were studied. Data at entry into the trial were used to classify patients according to CTC. Survival curves for up to 16 years were made, and survival rates were compared using the log-rank test. Survival decreased significantly with increasing degree of abnormality (A----B----C) of albumin (p less than 0.001), ascites (p less than 0.001), bilirubin (p = 0.02) and nutritional status (p = 0.03). Survival was insignificantly influenced by neurological status (p = 0.11) probably because none of the patients had hepatic coma at entry into the trial. The five variables in CTC were combined to a score. With increasing score, the median survival time decreased from 6.4 years (score 5) to 2 months (scores 12 or more). Furthermore, the mortality from hepatic failure, gastrointestinal bleeding or hepatocellular carcinoma increased significantly with increasing score. CTC provide valuable and easily obtainable prognostic information in cirrhosis. However, CTC are inferior to a prognostic index based on multivariate analysis of prognostic factors.

Actuarial Analysis↗
PubMedDate not supplied

Psychiatric admissions and choice of abortion.

A statistical analysis is presented of the intensities of admissions to psychiatric hospitals among women in Denmark who either gave birth to a child in the year 1975 or had an induced abortion in the same year. The models used are time-continuous Markov and semi-Markov processes, and the methods employed include non-parametric and semi-parametric analysis of counting processes. The influence of prior psychiatric admissions on the choice of terminating the pregnancy with an induced abortion is also studied.

Abortion, Induced↗
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In B-cell chronic lymphocytic leukaemia chromosome 17 abnormalities and not trisomy 12 are the single most important cytogenetic abnormalities for the prognosis: a cytogenetic and immunophenotypic study of 480 unselected newly diagnosed patients.

Of 560 consecutive, newly diagnosed untreated patients with B CLL submitted for chromosome study, G-banded karyotypes could be obtained in 480 cases (86%). Of these, 345 (72%) had normal karyotypes and 135 (28%) had clonal chromosome abnormalities: trisomy 12 (+12) was found in 40 cases, 20 as +12 alone (+12single), 20 as +12 with additional abnormalities (+12complex). Other frequent findings included abnormalities of 14q, chromosome 17, 13q and 6q. The immunophenotype was typical for CLL in 358 patients (CD5+, Slg(weak), mainly FMC7-) and atypical for CLL in 122 patients (25%) (CD5-, or Slg(strong) or FMC7+). Chromosome abnormalities were found significantly more often in patients with atypical (48%) than in patients with typical CLL phenotype (22%) (P < 0.00005). Also +12complex, 14q+, del6q, and abnormalities of chromosome 17 were significantly more frequent in patients with atypical CLL phenotype, whereas +12single was found equally often in patients with typical and atypical CLL phenotype. The cytomorphology of most of the +12 patients was that of classical CLL irrespective of phenotype. In univariate survival analysis the following cytogenetic findings were significantly correlated to a poor prognosis: chromosome 17 abnormalities, 14q+, an abnormal karyotype, +12complex, more than one cytogenetic event, and the relative number of abnormal mitoses. In multivariate survival analysis chromosome 17 abnormalities were the only cytogenetic findings with independent prognostic value irrespective of immunophenotype. We conclude that in patients with typical CLL immunophenotype, chromosome abnormalities are somewhat less frequent at the time of diagnosis than hitherto believed. +12single is compatible with classical CLL, and has no prognostic influence whereas chromosome 17 abnormalities signify a poor prognosis. In patients with an atypical CLL immunophenotype, chromosome abnormalities including +12complex, 14q+, del 6q and chromosome 17 are found in about 50% of the patients, and in particular chromosome 17 abnormalities suggest a poor prognosis.

Aged↗
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Predictors of recurrence in affective disorder--analyses accounting for individual heterogeneity.

BACKGROUND: Previous studies suggest that gender, age at onset, and marital status act as risk factors for further recurrence initially during the course of affective disorder but not at a later stage. These studies did, however, not take the individual liability to recurrence into account. METHOD: The effect of predictors of recurrence was estimated with the use of generalised linear mixed models in a case register study including a random sample of all patients admitted with primary affective disorder in Denmark during 1971-1993. RESULTS: In total, 7047 first admission patients with a diagnosis of affective disorder, depressive or manic/circular type were included in the analyses. The study confirmed that the effect of the type of disorder, age at first admission, and never being married decreased during the course of illness even when the individual liability to recurrence was taken into account. No differences in the effect of gender and in the effect of a recent divorce were found between early and later episodes and the effect of a recent death of a spouse seemed to increase during the course of illness. The risk of recurrence increased with every new episode for all sub-groups of patients. CONCLUSION: The effect of some, but not all, predictors of recurrence decline during the course of affective illness. The number of previous episodes predicts recurrence in most subgroups of patients. LIMITATION: The data relate to re-admissions rather than recurrence. CLINICAL RELEVANCE: The study underscores the importance of the illness process itself.

Adult↗