[German acupuncture studies].
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Acupuncture Therapy↗
Biomedical subjects
Jörg Michaelis
Publications and source records attributed to Jörg Michaelis.
Lead-time and overdiagnosis estimation in neuroblastoma screening.
In Germany, neuroblastoma is the most frequent extracranial solid childhood tumour. Its properties made it seem an ideal candidate for screening. A German trial assessed the effect of screening at one year of age from 1995-2001 in a nationwide project. We present here the methods developed for the estimation of lead-time and overdiagnosis in this project. Follow up on 1.5 million screened children and 2.1 million control children is currently available until June 2002. Ascertainment of control cohort cases and false negative cases is complete up to this date. A method for determining an empirical lead-time distribution and overdiagnosis estimate from comparing the age specific incidences in the control group and the study group is presented. Lead-time leads to an excess of cases in the screening group at the screening age and cases missing at higher age. If more cases are observed at the screening age than can be explained by lead-time, the difference is attributed to overdiagnosis. The width of the screening age window and the empirical maximum lead-time have to be chosen from graphs. About 1.0/100000 cases (20 per cent of the possible cases) experienced lead-time while 6.8/100000 cases were overdiagnosed. The mean lead-time was estimated to be about 15 months. The number of cases who might benefit is much smaller than was expected before the study while the overdiagnosed group is much larger. The method is robust against the choices that have to be made in the estimation process.
Age Distribution↗
Atopic disease and childhood acute lymphoblastic leukemia.
Our objective was to test the hypothesis that the risk of childhood leukemia is associated with allergies or a family history of allergy. We used a German population-based case-control study with self-reported information on allergies of the children and their first-degree relatives. Our study included a total of 1,130 cases of acute lymphoblastic leukemia (ALL), 164 cases of acute myeloid leukemia (AML) and 2,957 controls. A major finding of our study is that hay fever, neurodermatitis and contact eczema are underrepresented within the group of children with ALL, with respective odds ratios (OR) of 0.45 (95% confidence interval [CI] 0.31-0.66) for hay fever, of 0.49 (CI 0.34-0.71) for neurodermatitis and of 0.62 (CI 0.39-0.99) for eczema, respectively. Atopic diseases, comprising hay fever, neurodermatitis and asthma, are much stronger related with a reduced risk of ALL than other allergies (OR 0.52, CI 0.40-0.67 vs. OR 0.89, CI 0.66-1.21). The strongest association is seen with an atopy in the index child; however, ALL risk is also reduced if one of the parents or a sibling had an atopic disease. No such consistent pattern is seen for AML. Our data suggest that atopy or a family history of atopy are associated with a reduced risk of childhood ALL. Recall bias remains a concern, but sensitivity analysis provided some evidence that the protective effect is unlikely to be attributable to this bias in its entirety.
Adolescent↗
Long-term survival of children with neuroblastoma prior to the neuroblastoma screening project in Germany.
BACKGROUND: In the last decades, prognosis of children with neuroblastoma has improved only slightly. Traditional estimates of survival reflect the survival experience of children diagnosed many years ago, and may thus not capture more recent progress in prognosis. We applied a new method of survival analysis, denoted period analysis, to provide more up-to-date estimates of long-term prognosis. We selected the cases diagnosed before the German neuroblastoma screening project in 1995, allowing to assess the method by comparing the 1994 projected survival estimates with the observations made today (2000). PROCEDURE: The data comes from the population based German Childhood Cancer Registry. We included all 1,353 children diagnosed with neuroblastoma below age 15 between 1980 and 1994. We derived 5-, 10-, and 15-year survival estimates using traditional analysis or period analysis as needed. Where possible we compared the period analysis estimates with the later obtained actual estimates. We showed trends in survival for the sample as a whole and for prognostic subgroups. RESULTS: Survival probabilities increased over time especially in the subgroups with poor prognosis. Short-term survival probabilities improved more than long-term survival probabilities. Evaluation of the period-analysis estimates showed them to provide accurate and timely projections of prognosis of newly diagnosed patients. CONCLUSIONS: The results suggest major improvements in prognosis of children with neuroblastoma, even prior to the start of the German neuroblastoma screening project, especially in advanced disease. This could have been disclosed with the application of the period analysis method in 1995 even then with considerable accuracy. We recommend a more widespread application of this method especially in population-based cancer registries.
Adolescent↗