著者
Michio Yamamoto Dai Keino Shinichiro Sumii Tomoko Yokosuka Hiroaki Goto Ayano Inui Tsuyoshi Sogo Makio Kawakami Mio Tanaka Masakatsu Yanagimachi
出版者
The Japanese Society of Internal Medicine
雑誌
Internal Medicine (ISSN:09182918)
巻号頁・発行日
pp.1308-22, (Released:2023-03-22)
参考文献数
17
被引用文献数
4

We herein report a case of hepatitis-associated aplastic anemia (HAAA) that occurred after severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) vaccination. In this patient, progressive pancytopenia observed two months after acute hepatitis following the second dose of the SARS-Cov-2 vaccine indicated the development of HAAA. Although some reports have suggested that SARS-Cov-2 vaccination may be involved in the development of autoimmune diseases, no cases of HAAA developing after SARS-Cov-2 vaccination have been reported. SARS-Cov-2 vaccination in children has only started relatively recently, so the range of side effects in children has not yet been thoroughly described. Therefore, we need to strengthen surveillance for symptoms of children who are vaccinated.
著者
Michio Yamamoto Dai Keino Shinichiro Sumii Tomoko Yokosuka Hiroaki Goto Ayano Inui Tsuyoshi Sogo Makio Kawakami Mio Tanaka Masakatsu Yanagimachi
出版者
The Japanese Society of Internal Medicine
雑誌
Internal Medicine (ISSN:09182918)
巻号頁・発行日
vol.62, no.12, pp.1813-1816, 2023-06-15 (Released:2023-06-15)
参考文献数
17
被引用文献数
4

We herein report a case of hepatitis-associated aplastic anemia (HAAA) that occurred after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. In this patient, progressive pancytopenia observed two months after acute hepatitis following the second dose of the SARS-CoV-2 vaccine indicated the development of HAAA. Although some reports have suggested that SARS-CoV-2 vaccination may be involved in the development of autoimmune diseases, no cases of HAAA developing after SARS-CoV-2 vaccination have been reported. SARS-CoV-2 vaccination in children has only started relatively recently, so the range of side effects in children has not yet been thoroughly described. Therefore, we need to strengthen surveillance for symptoms of children who are vaccinated.
著者
Etsuji Suzuki Michio Yamamoto Eiji Yamamoto
出版者
Japan Epidemiological Association
雑誌
Journal of Epidemiology (ISSN:09175040)
巻号頁・発行日
pp.JE20210352, (Released:2022-01-22)
参考文献数
26

Background: The counterfactual definition of confounding is often explained in the context of exchangeability between the exposed and unexposed groups. One recent approach is to examine whether the measures of association (e.g., associational risk difference) are exchangeable when exposure status is flipped in the population of interest. We discuss the meaning and utility of this approach, showing their relationships with the concept of confounding in the counterfactual framework.Methods: Three hypothetical cohort studies are used, in which the target population is the total population. After providing an overview of the notions of confounding in distribution and in measure, we discuss the approach from the perspective of exchangeability of measures of association (e.g., factual associational risk difference vs. counterfactual associational risk difference).Results: In general, if the measures of association are non-exchangeable when exposure status is flipped, confounding in distribution is always present, although confounding in measure may or may not be present. Even if the measures of association are exchangeable when exposure status is flipped, there could be confounding both in distribution and in measure. When we use risk difference or risk ratio as a measure of interest and the exposure prevalence in the population is 0.5, testing the exchangeability of measures of association is equivalent to testing the absence of confounding in the corresponding measures.Conclusions: The approach based on exchangeability of measures of association essentially does not provide a definition of confounding in the counterfactual framework. Subtly differing notions of confounding should be distinguished carefully.
著者
Etsuji Suzuki Michio Yamamoto Eiji Yamamoto
出版者
Japan Epidemiological Association
雑誌
Journal of Epidemiology (ISSN:09175040)
巻号頁・発行日
vol.33, no.8, pp.385-389, 2023-08-05 (Released:2023-08-05)
参考文献数
26

Background: The counterfactual definition of confounding is often explained in the context of exchangeability between the exposed and unexposed groups. One recent approach is to examine whether the measures of association (eg, associational risk difference) are exchangeable when exposure status is flipped in the population of interest. We discuss the meaning and utility of this approach, showing their relationships with the concept of confounding in the counterfactual framework.Methods: Three hypothetical cohort studies are used, in which the target population is the total population. After providing an overview of the notions of confounding in distribution and in measure, we discuss the approach from the perspective of exchangeability of measures of association (eg, factual associational risk difference vs counterfactual associational risk difference).Results: In general, if the measures of association are non-exchangeable when exposure status is flipped, confounding in distribution is always present, although confounding in measure may or may not be present. Even if the measures of association are exchangeable when exposure status is flipped, there could be confounding both in distribution and in measure. When we use risk difference or risk ratio as a measure of interest and the exposure prevalence in the population is 0.5, testing the exchangeability of measures of association is equivalent to testing the absence of confounding in the corresponding measures.Conclusion: The approach based on exchangeability of measures of association essentially does not provide a definition of confounding in the counterfactual framework. Subtly differing notions of confounding should be distinguished carefully.