Tokyo, Aug. 16 -- UMIN Clinical Trials Registry (UMIN-CTR) received information related to the study (UMIN000062505) titled 'A study of whether prescribing oral doxycycline or minocycline after an asymptomatic tick bite reduces the risk of developing Japanese spotted fever on days 3-14, using health insurance claims data (target trial emulation)' on Aug. 7.

Study Type: Observational

Primary Sponsor: Institute - The University of Osaka, Graduate School of Medicine Faculty of Medicine

Condition: Condition - Tick bite (asymptomatic outpatient visit). The outcome is Japanese spotted fever (Rickettsia japonica infection). Classification by malignancy - Others Genomic information - NO

Objective: Narrative objectives1 - Using the JMDC claims database, to estimate whether, among asymptomatic patients presenting to outpatient care with a new tick bite, a policy of prescribing oral doxycycline or minocycline at time zero (Day 0) reduces the day 3-14 risk of Japanese spotted fever diagnosis, compared with a policy of prescribing no systemic antibiotic at Day 0, within a target trial emulation framework. Database-specific propensity-score stabilized IPTW is used to estimate standardized 14-day risk differences and risk ratios (prescription-policy effect; facility-cluster 95% CI). This registration is performed before analysis and without reference to outcomes. Basic objectives2 - Efficacy

Eligibility: Age-lower limit - Not applicable Age-upper limit - Not applicable Gender - Male and Female Key inclusion criteria - (1) Patients of all ages receiving outpatient care in Japan for a newly recorded tick bite. (2) At least 365 days of observability before time zero (Day 0). (3) No recorded tick bite in the prior 90 days. (4) No Japanese spotted fever on Day 0 or in the prior 30 days. (5) No fever, rash, hospitalization, or severe-infection signs on Day 0 (asymptomatic). (6) No contraindication to the target drugs (oral doxycycline or minocycline) and no clear treatment indication from another condition. Hokkaido is excluded if regional information is available. The main analysis uses only the first eligible episode per patient. The study period for the insurer database is April 2012 to December 2025. Key exclusion criteria - (1) Fever, rash, hospitalization, or severe-infection signs on Day 0 (symptomatic). (2) A recorded tick bite in the prior 90 days. (3) Japanese spotted fever on Day 0 or in the prior 30 days. (4) Less than 365 days of observability. (5) A contraindication to the target drugs or a clear treatment indication from another condition. (6) Hokkaido, when the region is identifiable. (7) In the main analysis, patients whose follow-up to Day 14 cannot be ensured (numbers and reasons reported by group). Target Size - 10000

Recruitment Status: Recruitment status - Preinitiation Date of protocol fixation - 2026 Year 04 Month 14 Day Date of IRB - 2026 Year 04 Month 14 Day Anticipated trial start date - 2026 Year 08 Month 07 Day Last follow-up date - 2027 Year 03 Month 31 Day

To know more, visit https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000071558

Disclaimer: Curated by HT Syndication.