Biomedical subjects

Christoffer Johansen

Publications and source records attributed to Christoffer Johansen.

58 records · Page 4Linked to original sources

PubMed2002

Validation of a job-exposure matrix for assessment of utility worker exposure to magnetic fields.

The aim of this study was to evaluate a 50-Hz electromagnetic field job-exposure matrix used in epidemiological studies of a nationwide cohort of utility workers in Denmark. We compared a job-exposure matrix that distinguished four categories of exposure to 50-Hz time-weighted average (TWA) magnetic fields: low (< 0.1 microT), medium (0.1-0.29 microT), high (0.3-0.99 microT) and very high (> 1.0 microT) of utility company employees with 196 measurements of 8-h exposure for 129 workers in this industry. The 129 workers were selected from the following five main work environments: generation facilities, transmission lines, distribution lines, substations, and other electrically and non-electrically relates jobs. This study shows that the job-exposure matrix can be expected to introduce misclassification mainly between adjacent categories of exposure. Thus, the distribution of measurements of exposure to 50-Hz magnetic fields was similar for workers in the medium and the high exposure matrix categories. But the two extreme categories satisfactorily separate low and very highly exposed workers. The study shows that epidemiological use of this job-exposure matrix might combine the two intermediate categories of exposure. If the sample size in extreme categories provides enough power, a study in which this job-exposure matrix is used should allow detection of a true association between exposure to 50-Hz magnetic field and disease.

Denmark↗

PubMed2002

Psychosocial home visits in cancer treatment: a qualitative study on the content of home visits.

As an initial part of a large randomized psychosocial intervention study on the effect of home visits to Danish patients with colorectal cancer, a qualitative interview study was performed to investigate how these home visits should be carried out. The study included 21 informants, consisting of a of patients with colorectal cancer, an of patients with breast cancer who had previously received home visits in another project, a of volunteers performing home visits, and a of researchers in the field of home visiting. The results of qualitative semistructured interviews were compared and analyzed. Common themes were identified and placed in a paradigm model. Respect for the patient as a fellow human being was a prerequisite for ensuring confidence and was chosen as the core category in the analysis. The analysis suggested that visits to patients' homes resulted in better balanced contacts than did visits at hospitals. Most patients requested personal involvement and continuity from their visitors, preferably a healthcare professional capable of providing health information and practical help. In conclusion, we expect that coping with the consequences of a diagnosis of cancer will be improved when patients are regarded as individuals rather than as objects. Home visits may facilitate this process.

Aged↗

PubMed2002

Cancer risk among pacemaker recipients in Denmark, 1982-1996.

To address concerns about the potential carcinogenicity of pacemakers, we launched the first epidemiologic study of cancer incidence among pacemaker recipients. A nationwide cohort of 16,357 pacemaker recipients in Denmark from 1982 through 1996 was identified. The Danish Cancer Registry was used to identify all incident cancers within the cohort, with almost 75,000 person-years of observation. The cohort had a slight excess of cancer overall (SIR = 1.19, 95% confidence interval [95% CI, 1.1-1.2]). This was largely caused by an elevated SIR for multiple myeloma among men (SIR = 1.78,95% CI, 1.1-2.8), which increased to 2.60 (95% CI, 0.9-5.7) 5-9 years after implantation, and to a similarly increased SIR for kidney cancer among women (SIR = 2.05, 95% CI, 1.3-3.0), which increased to 3.39 (95% CI, 1.6-6.2) after a latency period of 5-9 years. An excess of urinary bladder cancer was also seen after 10 years. No excess risk was observed for breast cancer or sarcomas, although the SIRs for sarcomas tended to increase over time, based on small numbers. Our results are largely reassuring but, as pacemakers become more common and are implanted at earlier ages and as survival following implantation improves, the excesses of bladder cancer, multiple myeloma among men, and kidney cancer among women with long-term followup warrant further investigation.

Aged↗

PubMedDate not supplied

Mortality and suicide among Danish women with cosmetic breast implants.

BACKGROUND: Epidemiologic studies indicate that women with cosmetic breast implants have a significantly increased risk of suicide. Our objectives were to examine mortality among Danish women who underwent cosmetic breast implant surgery and to evaluate the baseline prevalence of psychopathological disorders as measured by admission to a psychiatric hospital among women seeking cosmetic surgery. METHODS: Cohort study of 2761 women who underwent cosmetic breast implant surgery at private clinics of plastic surgery or public hospitals, 7071 women who underwent breast reduction surgery at public hospitals, and 1736 women who attended private clinics for cosmetic surgery other than breast implantation, between 1973 and 1995. Causes of death through 1999 were identified through the Danish Mortality Files. Information on admission to psychiatric hospitals prior to cosmetic surgery was obtained from the Danish Psychiatric Central Register. RESULTS: Women with cosmetic breast implants had significantly elevated standardized mortality ratios (SMRs) for death overall (SMR, 1.4; 95% confidence interval [CI], 1.1-1.7), nonmalignant lung disease (3.4; 95% CI, 1.4-6.9), and suicide (SMR, 3.1; 95% CI, 1.7-5.2). Women who underwent breast reduction exhibited low SMRs for death overall (0.7; 95% CI, 0.7-0.8) and several specific causes, including breast cancer (0.4; 95% CI, 0.2-0.6), whereas death from suicide was moderately above expectation (SMR, 1.6; 95% CI, 1.0-2.5). The prevalence of psychiatric admission prior to cosmetic surgery was higher among women who underwent cosmetic breast implant surgery (8.0%; 95% CI, 7.0%-9.0%) than among women who underwent breast reduction (4.7%; 95% CI, 4.2%-5.2%) or other cosmetic procedures (5.5%; 95% CI, 4.5%-6.7%). When compared with all control groups, women with cosmetic implants had an odds ratio for prior psychiatric admission of 1.7 (95% CI, 1.4-2.0). CONCLUSIONS: Danish women with cosmetic breast implants experienced higher overall mortality compared with women in the general population owing in part to a 3-fold increase in suicide. Women with breast reduction had a low total and cause-specific mortality but a moderate excess risk of suicide. For the first time, to our knowledge, we found evidence of an increased prevalence of mental illness as measured by admission to a psychiatric hospital prior to implant surgery among women receiving cosmetic breast implants. Studies are needed to clarify the underlying reasons for the consistently reported 2- to 3-fold excess of suicide among women with cosmetic breast implants.

Adolescent↗