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Biomedical subjects

P K Andersen

Publications and source records attributed to P K Andersen.

At least 109 records · Page 6Linked to original sources
PubMed1987

Unemployment and mortality in Denmark, 1970-80.

Relative mortality in the period 1970-80 was studied among Danish men and women who were unemployed and employed on the day of the 1970 census. The study population consisted of the total labour force in the age range 20-64 on 9 November 1970--that is, about 2 million employed and 22,000 unemployed people. Relative mortality was analysed by a multiplicative hazard regression model (as a natural extension of the standardised mortality ratio) and a multiplicative regression model with extra-Poisson variation. A significantly increased death rate (40-50%) was found among the unemployed after adjusting for occupation, housing category, geographical region, and marital state. Analysis of five main causes of death showed increased mortality from all causes, but especially from suicide or accidents. In areas where the local unemployment rate was comparatively high the relative mortality among the unemployed was lower. The increased mortality among the unemployed was interpreted as a consequence of health related selection as well as increased susceptibility associated with the psychosocial stress of unemployment.

Adult↗
PubMed1987

Determinants of complete remission induction and maintenance in chemotherapy with or without irradiation of small cell lung cancer.

The possible influence of pretreatment patient characteristics upon the probabilities of complete remission (CR) induction and maintenance was investigated in a series of 815 nonresected patients with small cell lung cancer. All patients underwent pretreatment staging which enabled allocation of 391 patients to trials for limited stage disease and 424 patients to trials for extensive disease. Three controlled trials for each disease stage were conducted between 1973 and 1981. All therapeutic regimens consisted of combinations of between three and six agents (lomustine, cyclophosphamide, methotrexate, vincristine, doxorubicin, etoposide) with or without irradiation. Thirty-five % of the limited stage patients and 18% of the extensive stage patients were alive and had achieved a complete remission 16 weeks after initiation of the treatment, i.e., after four cycles of chemotherapy. Relationships between pretreatment characteristics and the probability to pass this benchmark were examined by logistic regression analysis. The probability of CR was negatively related to increased serum lactate dehydrogenase and male sex in both disease stages. Pretreatment anemia (less than 12 g/liter) and poor performance status were associated with a reduced CR rate in limited and extensive stage disease, respectively. Factors related to the maintenance of complete remission were subsequently examined in the 211 complete responders by use of Cox's regression analysis. Complete responders with extensive disease prior to treatment had greater cumulative risk of relapse than those with limited disease (P less than 0.01). Hyponatremia had a significant negative influence on the remission duration in limited disease while age greater than 60 years and bone marrow metastases had significantly negative influence in extensive disease. Using the models it was possible to identify subgroups of patients with CR rates ranging from 5 to 55% and to stratify complete responders according to estimated risks of subsequent relapse.

Adult↗
PubMed1987

Conditional power calculations as an aid in the decision whether to continue a clinical trial.

It is shown how stochastically curtailed testing can be included in the process of deciding whether to continue a clinical trial in which survival times or times to some other event in two treatment arms are compared. A model with constant intensities is used. One examines the power function of the test which would be computed if the trial were prolonged, conditional on the course of the trial up to the time of decision.

Clinical Trials as Topic↗
PubMed1986

Long-term disease-free survival in small-cell carcinoma of the lung: a study of clinical determinants.

The influence of treatment and of pretreatment patient characteristics on the probability of long-term disease-free survival in small-cell lung cancer (SCLC) was investigated in a consecutive series of 874 patients. The patients were included in six controlled treatment trials from 1973 to 1981, using different combinations of chemotherapy with or without irradiation. All patients underwent pretreatment staging, including bronchoscopy, peritoneoscopy with liver biopsy, and bone marrow examination. The same procedures were repeated in patients without overt signs of disease 18 months from initiation of treatment, and patients without evidence of SCLC were regarded as long-term survivors. Seventy-two patients were disease-free at restaging, corresponding to 13% of 443 patients with limited-stage disease and 3% of 431 patients with extensive-stage disease. The possible relationship between different pretreatment variables and the probability of 18 months' disease-free survival was investigated by multiple regression analysis. Disease extent was the most important determinant of long-term survival. Being a woman was a positive factor and hypouricemia had negative influence on the long-term results, while features such as performance status and serum lactate dehydrogenase (LDH) did not have significant influence in the regression model. Differences between the efficacy of the applied treatment regimens were less in limited disease than they were in extensive disease, in which six-agent regimens of alternating chemotherapy was significantly better than treatment with three- or four-agent regimens. Accordingly, disease extent seems to be the most pivotal determinant of long-term survival in SCLC, but influence of the patient's sex and serum urate concentration should also be considered.

Adolescent↗
PubMed1986

Updating prognosis and therapeutic effect evaluation in cirrhosis with Cox's multiple regression model for time-dependent variables.

A multivariate Cox regression analysis with time-dependent variables has been performed on the data of 415 patients with cirrhosis included in a controlled clinical trial of 10-15 mg prednisone daily versus placebo. The analysis showed that a poor prognosis was associated with a low prothrombin index, marked ascites, GI bleeding, high age, high daily alcohol consumption, high bilirubin and alkaline phosphatase and low albumin values, little liver connective tissue inflammation, and poor nutritional status. Prothrombin index and ascites showed significant interaction with the treatment in such a manner that high prothrombin index and absence of ascites were associated with a beneficial effect of prednisone, whereas low prothrombin index and presence of ascites were associated with a harmful effect of prednisone treatment. The final model was validated in independent patients by comparing their actual survival with that predicted from the model, using a split-sample testing technique. The prognostic factors were combined with an index that can be used to update prognosis whenever changes occur in the clinical status of a patient during the course of the disease. The probability of surviving the next 3 or 6 months can be estimated from the prognostic index at any time during the course. The index may be of value for the correct timing of special therapeutic procedures such as liver transplantation.

Adult↗
PubMed1986

Prognostic factors in small cell lung cancer: multivariate model based on 778 patients treated with chemotherapy with or without irradiation.

The relationships between prognostic factors and duration of survival in small cell lung cancer were investigated in a consecutive series of 874 patients treated with combination chemotherapy with or without irradiation. The series included 443 patients with limited and 431 patients with extensive stage disease based on staging including bone marrow examination and peritoneoscopy with liver biopsy but no routine scans. The median durations of survival for the two disease categories were 48 and 30 weeks, respectively. The influence on survival of various pretreatment factors was investigated by use of univariate methods and Cox's multivariate regression model. Patients in each stage were treated according to one of three controlled trials. Variations among the applied treatment regimens did not result in significant differences in duration of survival among patients with limited disease. An alternating regimen was superior to continuous therapy in patients with extensive disease and raised serum lactate dehydrogenase. Prognosis was correlated with disease extent. Surgical resection as well as limited stage disease thus both contributed to survival. Poor performance status, reduced hemoglobin concentration, and raised values for serum lactate dehydrogenase were significantly associated with a reduced duration of survival in both stages. Females with limited disease lived significantly longer than males while advanced age was a negative prognostic factor in extensive disease. Plasma sodium and serum urate were both predictive of survival in limited disease. Proved metastatic disease affecting specific sites or total number of metastatic sites did not carry significant prognostic information in a model including a general variable characterizing stage of disease. Fifty of the 778 patients, on whom the multiple regression model was based, were alive and disease free 2 years after the start of the treatment. Two-year survival rates were strongly correlated to groupings based on prognostic factors, and information about disease extent was not mandatory for predicting the probability of long term disease-free survival.

Adult↗
PubMed1985

Low plasma fibronectin after drowning.

The plasma concentrations of fibronectin were zero for 8 days in a 53-year-old male who was submersed for 5 min, but conscious at the time of admission to hospital. The patient developed multiple organ failure, disseminated intravascular coagulation and finally died after 15 days. The low fibronectin values indicate prolonged severe reticulo-endothelial failure, and may be a prognostic sign in cases of drowning or asphyxia of other etiologies.

Combined Modality Therapy↗
PubMed1985

The effect of proteinuria on relative mortality in type 1 (insulin-dependent) diabetes mellitus.

We followed 1,134 patients with Type 1 (insulin-dependent) diabetes, diagnosed between 1933 and 1952, until 1982 or death or until their emigration. Their age at onset of diabetes was under 31 years. Information concerning the development of persistent proteinuria was sought in every case. In 104 cases, the data were either questionable or the patient could not be traced. Twenty-nine patients developed non-diabetic proteinuria. Among the remaining 1,001 patients, 406 developed persistent proteinuria (350 died) and 595 did not (166 died). The incidence of persistent proteinuria was highest among men; it decreased with increasing year of diabetes onset from 1933 to 1952, and decreased with increasing age at onset. The relative mortality was extremely high among patients with persistent proteinuria, increasing to a maximum of about 100 at age 35 years. Patients not developing proteinuria had a relatively constant low relative mortality of about 2. The decreasing incidence of persistent proteinuria and the decreasing mortality with increasing calendar year of diabetes onset resulted in a 50% increase in life-expectancy among patients diagnosed in 1950 compared with patients diagnosed in 1935. In patients who developed persistent proteinuria, relative mortality was higher in women than men at all ages. In patients who did not develop proteinuria, relative mortality was similar in men and women after the age of 35. Uraemia was the main cause of death in patients with persistent proteinuria, although cardiovascular deaths were more frequent than in patients without proteinuria. Thus, proteinuria is associated not only with death from uraemia but also from cardiovascular disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Denmark↗
PubMed1985

Relative mortality of type 1 (insulin-dependent) diabetes in Denmark: 1933-1981.

The relative mortality of Type 1 (insulin-dependent) diabetes in Denmark during the period 1933-1981 was studied using a modification of Cox's regression model on the basis of two patient populations, ascertained in different ways and independently of each other. Initial analysis showed that the two groups could be combined completely into one common analysis. Relative mortality was the same for both sexes. The additional variables studied were age at diagnosis, current age, calendar year at diagnosis and calendar time during follow-up. All these interrelated variables were accounted for in the analysis. The analysis showed that relative mortality decreased with increasing age at diagnosis; increased from 1933 to a maximum in about 1965, after which it decreased; increased with increased duration of diabetes to a maximum at 15-25 years, after which it declined.

Adolescent↗
PubMed1985

A therapeutic index that predicts the individual effects of prednisone in patients with cirrhosis.

Our aim was to construct an index that accurately predicts the degree of benefit or harm that prednisone therapy holds for patients with liver cirrhosis. The admission and survival data of 488 patients with cirrhosis who participated in a controlled clinical trial of prednisone in a dosage of 10-15 mg daily (251 patients) versus placebo (237 patients) and who were observed for up to 12 yr were analyzed using Cox's multiple regression model. Four variables each provided significant therapeutic information: antinuclear factor (p = 0.02) and large piecemeal necroses (p = 0.02) were associated with a beneficial effect, whereas ascites (p = 0.0004) and large regenerative nodules (p = 0.0007) were associated with a harmful effect of prednisone. From these four variables a therapeutic index was constructed. For a given patient the therapeutic index is a measure of how big the effect will be if prednisone is given. The gain in survival time obtained by administering prednisone according to the therapeutic index was estimated to be 349 yr, mainly confined to 217 patients with a significant positive (121) or negative (96) therapeutic index. The therapeutic index may prove useful for the optimal administration of prednisone treatment in new patients with cirrhosis.

Antibodies, Antinuclear↗
PubMed1985

Buprenorphine-supplemented anaesthesia. Influence of dose on duration of analgesia after cholecystectomy.

Fifty-one patients undergoing cholecystectomy received a single dose of buprenorphine 4.5-12 micrograms kg-1 at induction. Median duration of analgesia after surgery was 6 h. Multiple regression analysis showed the duration of analgesia to be slightly dependent on the age of the patient. No relationship was found between the duration of analgesia and the weight-related dose of buprenorphine, the age, sex or body weight of the patient, the duration of anaesthesia, or the dose of droperidol or thiopentone administered.

Adjuvants, Anesthesia↗
PubMed1985

Postoperative pain treatment after upper abdominal surgery with epidural morphine at thoracic or lumbar level.

Thirty patients undergoing upper laparotomy were entered into a randomized trial, comparing the effect of midthoracic (T) and lumbar (L) epidural morphine on postoperative pain and pulmonary function. Five mg morphine was injected through the catheter at the end of the operation, and subsequently three times a day. Six, 30 and 54 h postoperatively, the following tests were performed: linear analogue pain score, arterial gas tensions (PaO2, PaCO2 and pH), forced ventilatory capacity (FVC), forced expiratory volume in 1s (FEV1) and peak expiratory flow rate (PEF). The changes in pain score (increase of the median): T: 21, 6, 5, and L: 24, 15, 8 per cent of full scale), PaO2 (decrease of the tension: T: 1.7, 2.1, 2.4, and L: 2.0, 2.8, 2.0 kPa), PaCO2, pH, FVC (decrease of the volume: T: 1.3, 1.1, 0.9, and L: 1.3, 1.3, 1.21), FEV1 and PEF from the preoperative tests were not significantly different. It is concluded that the clinical effect of epidural morphine for postoperative pain treatment is the same or little different whether the administration takes place at the thoracic or lumbar level.

Abdomen↗