Association of longitudinal pet ownership with wheezing in 3-year-old children using the distributed lag model: the Japan Environment and Children's Study.

BACKGROUND: Time-varying exposures like pet ownership pose challenges for identifying critical windows due to multicollinearity when modeled simultaneously. The Distributed Lag Model (DLM) estimates critical windows for time-varying exposures, which are mainly continuous variables. However, applying complex functions such as high-order splines and nonlinear functions within DLMs may not be suitable for situations with limited time points or binary exposure, such as in questionnaire surveys. OBJECTIVES: (1) We examined the estimation performance of a simple DLM with fractional polynomial function for time-varying binary exposures through simulation experiments. (2) We evaluated the impact of pet ownership on childhood wheezing onset and estimate critical windows. METHODS: (1) We compared logistic regression including time-varying exposure in separate models, in one model simultaneously, and using DLM. For evaluation, we employed bias, empirical standard error (EmpSE), and mean squared error (MSE). (2) The Japan Environment and Children's Study (JECS) is a prospective birth cohort study of approximately 100,000 parent-child pairs, registered across Japan from 2011 to 2014. We applied DLM to the JECS data up to age 3. The estimated odds ratios (OR) were considered to be within critical windows when they were significant at the 5% level. RESULTS: (1) DLM and the separate model exhibited lower bias compared to the simultaneously model. Additionally, both DLM and the simultaneously model demonstrated lower EmpSEs than the separate model. In all scenarios, DLM had lower MSEs than the other methods. Specifically, where critical windows is clearly present and exposure correlation is high, DLM showed MSEs about 1/2 to 1/200 of those of other models. (2) Application of DLM to the JECS data showed that, unlike other models, a significant exposure effect was observed only between the ages of 0 and 6 months. During that periods, the highest ORs were 1.07 (95% confidence interval, 1.01 to 1.14) , observed between the ages of 2 and 5 months. CONCLUSIONS: (1) A simple DLM improves the accuracy of exposure effect and critical windows estimation. (2) 0-6 months may be the critical windows for the effect of pet ownership on the wheezing onset at 3 years.

Handling of outcome missing data dependent on measured or unmeasured background factors in micro-randomized trial: Simulation and application study.

Background: Micro-randomized trials (MRTs) enhance the effects of mHealth by determining the optimal components, timings, and frequency of interventions. Appropriate handling of missing values is crucial in clinical research; however, it remains insufficiently explored in the context of MRTs. Our study aimed to investigate appropriate methods for missing data in simple MRTs with uniform intervention randomization and no time-dependent covariates. We focused on outcome missing data depending on the participants' background factors. Methods: We evaluated the performance of the available data analysis (AD) and the multiple imputation in generalized estimating equations (GEE) and random effects model (RE) through simulations. The scenarios were examined based on the presence of unmeasured background factors and the presence of interaction effects. We conducted the regression and propensity score methods as multiple imputation. These missing data handling methods were also applied to actual MRT data. Results: Without the interaction effect, AD was biased for GEE, but there was almost no bias for RE. With the interaction effect, estimates were biased for both. For multiple imputation, regression methods estimated without bias when the imputation models were correct, but bias occurred when the models were incorrect. However, this bias was reduced by including the random effects in the imputation model. In the propensity score method, bias occurred even when the missing probability model was correct. Conclusions: Without the interaction effect, AD of RE was preferable. When employing GEE or anticipating interactions, we recommend the multiple imputation, especially with regression methods, including individual-level random effects.

Correlation of multiple endpoints in the first-line chemotherapy of advanced gastric cancer: Pooled analysis of individual patient data from Japanese Phase III trials.

BACKGROUND: Individual-level surrogates are important for management in patients treated for advanced gastric cancer (AGC). This study aimed to comprehensively investigate the correlation of multiple clinical endpoints in the first-line chemotherapy of AGC. METHODS: Individual patient data (IPD) were collected from four Japanese Phase III trials comparing S-1-based first-line chemotherapies (SPIRITS, START, GC0301/TOP-002, and G-SOX trials). Patients without Response Evaluation Criteria in Solid Tumors (RECIST)-based radiological assessments were excluded. Spearman's rank correlation coefficient was tested for correlation among overall survival (OS), progression-free survival (PFS), and postprogression survival (PPS). OS, PFS, and PPS were compared between responders (best response: complete response or partial response) and nonresponders (best response: stable disease or progressive disease). RESULTS: The study included a total of 1492 patients. Eighty percent of the patients (n = 1190) received subsequent chemotherapies after the failure of each trial's treatment protocol. PFS moderately correlated with OS (Spearman correlation coefficient = 0.66, p < 0.005), whereas the correlation between PPS and OS was strong (Spearman correlation coefficient = 0.87, p < 0.005). Responders had significantly longer OS (median, 17.7 vs. 9.1 months, p < 0.005), PFS (median, 6.9 vs. 2.8 months, p < 0.005), and PPS (median, 10.5 vs. 6.0 months, p < 0.005) than nonresponders. CONCLUSIONS: Our results reacknowledged the mild surrogacy of PFS and importance of postprogression treatments in patients with AGC receiving first-line chemotherapy. Consistent longer survival outcomes in better RECIST categories suggested that tumor response might be a useful individual-level surrogate.

Safety and efficacy of rituximab in systemic sclerosis (DESIRES): open-label extension of a double-blind, investigators-initiated, randomised, placebo-controlled trial.

BACKGROUND: Results from the double-blind phase 2 DESIRES trial showed that rituximab improves skin thickening in systemic sclerosis. Here, we present the findings of a subsequent 24-week open-label extension phase. METHODS: Patients with systemic sclerosis aged 20-79 years, who fulfilled the 2013 American College of Rheumatology and European League Against Rheumatism classification criteria, with a baseline modified Rodnan Skin Score (mRSS) of 10 or greater were enrolled into the DESIRES trial, which was an investigator-initiated, phase 2, double-blind, randomised controlled trial of rituximab versus placebo conducted at four sites in Japan. After completion of 24 weeks of treatment with either rituximab or placebo, patients in both groups received a further 24 weeks of rituximab (375 mg/m2 intravenously, once per week for 4 consecutive weeks) in an open-label extension. The primary endpoint of the double-blind trial was mRSS at week 24, which was reassessed at week 48 in the open-label extension. All endpoints were exploratory. Safety analyses included all participants who received at least one dose of study drug; efficacy analyses included those who had received at least one dose and undergone efficacy assessment at 24 weeks in the double-blind phase and at 48 weeks in the extension phase. The DESIRES study is registered with ClinicalTrials.gov, NCT04274257, and UMIN-CTR, UMIN000030139. FINDINGS: Between Nov 28, 2017, and Nov 6, 2018, 56 patients were randomly assigned to either rituximab (n=28) or placebo (n=28) in a double-blind study. 26 patients initially assigned to rituximab and 20 assigned to placebo transitioned to the open-label extension and all received at least one dose of rituximab; 24 participants in the rituximab-rituximab group and 19 in the placebo-rituximab group completed the extension phase. In the rituximab-rituximab group, there was an improvement in mRSS from baseline at week 24 (-5·81 [SD 3·16]), with further improvement at week 48 (-8·88 [3·10]). In the placebo-rituximab group, mRSS worsened at week 24 (2·14 [SD 5·51]) but improved at the week 48 assessment (-6·05 [4·43]). One patient each in the rituximab-rituximab and placebo-rituximab groups experienced one serious adverse event during the open-label phase (cholangitis and pneumococcal pneumonia, respectively). There were no deaths during follow-up. INTERPRETATION: Two courses of rituximab is a safe treatment that can provide sustained improvement in systemic sclerosis for at least 48 weeks. FUNDING: Japan Agency for Medical Research and Development. TRANSLATION: For the Japanese translation of the abstract see Supplementary Materials section.

Safety and efficacy of rituximab in systemic sclerosis (DESIRES): a double-blind, investigator-initiated, randomised, placebo-controlled trial.

BACKGROUND: Systemic sclerosis is a connective tissue disease characterised by multiorgan fibrosis with an autoimmune background and poor prognosis. Although a few drugs have shown some efficacy in treating the disease, there remains a great unmet medical need. We aimed to investigate the efficacy and safety of rituximab in patients with systemic sclerosis. METHODS: We did a double-blind, investigator-initiated, randomised, placebo-controlled trial at four hospitals in Japan. Patients aged 20-79 years, who fulfilled the 2013 American College of Rheumatology and European League Against Rheumatism classification criteria for systemic sclerosis, with a modified Rodnan Skin Score (mRSS) of 10 or greater, and an expected survival of at least 6 months were randomly assigned (1:1) to receive intravenous rituximab (375 mg/m2) or placebo once per week for 4 weeks. Patients and investigators were masked to treatment allocation. The primary endpoint was the absolute change in mRSS 24 weeks after initiation of study treatment, measured in all patients who received at least one dose of study treatment and had one endpoint assessment. This study is registered with ClinicalTrials.gov, NCT04274257, and UMIN-CTR, UMIN000030139. FINDINGS: Between Nov 28, 2017, and Nov 6, 2018, 80 individuals were screened and 56 (70%) were enrolled and randomly assigned; 51 (91%) were women and five (9%) were men. 27 (96%) of 28 patients in the rituximab group and 22 (79%) of 28 patients in the placebo group received at least one dose of their allocated treatment and completed 24 weeks of follow-up. The absolute change in mRSS 24 weeks after initiation of study treatment was lower in the rituximab group than in the placebo group (-6·30 in the rituximab group vs 2·14 in the placebo group; difference -8·44 [95% CI -11·00 to -5·88]; p<0·0001). Adverse events were similar in both groups and occurred in 28 (100%) of 28 patients in the rituximab group and 23 (88%) of 26 patients in the placebo group. One serious adverse event leading to treatment discontinuation occurred in one patient in each group (decreased serum albumin in the rituximab group and biliary enzyme increase in the placebo group). The most common adverse event was upper respiratory infection, which occurred in 11 patients (39%) in the rituximab group and ten patients (38%) in the placebo group. There were no deaths during follow-up. INTERPRETATION: Rituximab appears to be an effective and safe treatment for systemic sclerosis. Although this study has some limitations, this is the first clinical trial to show efficacy of rituximab with skin sclerosis as the primary endpoint. FUNDING: Japan Agency for Medical Research and Development (AMED), Zenyaku Kogyo. TRANSLATION: For the Japanese translation of the abstract see Supplementary Materials section.