Clinical Epidemiology (Mar 2021)
Validity of Self-Reported Diagnosis of Osteoporosis in Japan Nurses’ Health Study
Abstract
Takumi Kurabayashi,1 Yuki Ideno,2 Kazue Nagai,3 Naho Maruoka,3 Kiyoshi Takamatsu,4 Toshiyuki Yasui,5 Kunihiko Hayashi3 1Department of Obstetrics and Gynecology, Niigata City General Hospital, Niigata, Japan; 2Gunma University Center for Mathematics and Data Science, Maebashi, Gunma, Japan; 3Department of International/Community Health Laboratory Sciences, Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan; 4Department of Obstetrics and Gynecology, Tokyo Dental College Ichikawa General Hospital, Chiba, Japan; 5Department of Reproductive and Menopausal Medicine, Institute of Biomedical Science, Tokushima University Graduate School, Tokushima, JapanCorrespondence: Takumi KurabayashiDepartment of Obstetrics & Gynecology, Niigata City General Hospital, 463-7, Shumoku, Chuo-ku, Niigata City, Niigata Prefecture, 950-1197, JapanTel +81-25-281-5151Fax +81-25-281-5169Email [email protected]: Although the validity of self-reported osteoporosis is often questioned, validation studies are lacking. This study was performed to investigate how well self-reported diagnoses of osteoporosis agreed with validated clinical information in young and middle-aged women in the Japan Nurses’ Health Study (JNHS), a nationwide prospective cohort study of nursing professionals.Patients and Methods: Data were reviewed for 15,717 subjects from the combined cohorts of the JNHS and a preceding pilot study (Gunma Nurses’ Health Study). The subjects’ mean age at the baseline (BL) survey was 41.6 ± 8.3 years, and the mean follow-up period was 11.5 ± 4.4 years. Participating nurses were mailed a follow-up questionnaire every 2 years. Respondents who self-reported a positive osteoporosis diagnosis during the study period were sent an additional confirmation questionnaire to corroborate the details.Results: The number (proportion) of women with osteoporosis was 884 (5.6%) [primary osteoporosis, 812 (5.2%); secondary osteoporosis, 72 (0.5%)]. The cumulative incidence of osteoporosis at the age of 40, 50, 60, 70, and 80 years was estimated to be 0.1% (95% confidence interval, 0.1– 0.2), 1.1% (0.9– 1.3), 7.7% (7.0– 8.4), 23.6% (21.6– 25.7), and 54.2% (40.2– 68.1), respectively. For BL and regular follow-up + expert review versus BL and regular follow-up + confirmation questionnaire + expert review, the positive predictive value (PPV) was 61.3% versus 85.6% and the negative predictive value (NPV) was 98.9% versus 98.2%, respectively.Conclusion: Self-reporting was associated with a high NPV for the incidence of osteoporosis. Although the PPV was slightly lower, additional corroborations by confirmation questionnaire might improve the PPV.Keywords: validation, self-reported diagnosis, osteoporosis, prospective cohort study, Japan Nurses’ Health Study