A common feature in cohort studies is when there is a baseline measurement of the continuous follow-up or outcome variable. Common examples include baseline measurements of physiological characteristics such as blood pressure or heart rate in studies where the outcome is post-baseline measurement of the same variable. Methods incorporating the propensity score are increasingly being used to estimate the effects of treatments using observational studies. We examined six methods for incorporating the baseline value of the follow-up variable when using propensity score matching or weighting. These methods differed according to whether the baseline value of the follow-up variable was included or excluded from the propensity score model, whether subsequent regression adjustment was conducted in the matched or weighted sample to adjust for the baseline value of the follow-up variable, and whether the analysis estimated the effect of treatment on the follow-up variable or on the change from baseline. We used Monte Carlo simulations with 750 scenarios. While no analytic method had uniformly superior performance, we provide the following recommendations: first, when using weighting and the ATE is the target estimand, use an augmented inverse probability weighted estimator or include the baseline value of the follow-up variable in the propensity score model and subsequently adjust for the baseline value of the follow-up variable in a regression model. Second, when the ATT is the target estimand, regardless of whether using weighting or matching, analyze change from baseline using a propensity score that excludes the baseline value of the follow-up variable.

BACKGROUND: Inadequate management of acute post-haemorrhoidectomy pain is a major concern. Optimal pain management is necessary to reduce acute postoperative pain and improve care quality. Therefore, we investigated the efficacy of postoperative pudendal nerve block (PNB) in reducing acute post-haemorrhoidectomy pain in Asian individuals.
METHODS: This retrospective cohort study analysed 108 adult patients with grade 3 haemorrhoids. Patients with anorectal cancer were excluded from this study. Among the 108 patients, 79 and 29 received spinal anaesthesia (SA) with PNB (SAPNB) and SA alone, respectively. Propensity score matching and inverse probability of treatment weighting were performed to adjust for the effects of confounders.
RESULTS: Patients receiving SAPNB had significantly lower postoperative pain scores 6, 12, and 18 h after haemorrhoidectomy but significantly higher postoperative pain scores 24 and 48 h after haemorrhoidectomy than did patients receiving SA alone. PNB, older age, female sex, reduced operation time, and absence of cardiovascular disease reduced the risk of moderate to severe postoperative pain. Only the addition of PNB was consistently associated with a reduced risk of moderate to severe pain 6, 12, and 18 h after haemorrhoidectomy. Patients receiving SAPNB had significantly lower risks of perianal swelling and urinary retention but a significantly higher risk of nausea than did those receiving SA alone. The two groups exhibited similarity in their rates of postoperative readmission because of poor pain management and their lengths of stay upon readmission.
CONCLUSIONS: The addition of PNB to SA may effectively reduce acute post-haemorrhoidectomy pain.

UNASSIGNED: The association of COVID-19 with hearing loss (HL) is unclear among young adults and needs to be investigated. This study was conducted to determine the association of COVID-19 with HL and sudden sensorineural hearing loss (SSNHL) in young adults.
UNASSIGNED: This nationwide population-based cohort study used data from the Korea Disease Control and Prevention Agency-COVID-19-National Health Insurance Service. The study population consisted of young adult citizens aged 20-39 years without a history of HL. All participants were followed up from July 1, 2022 until HL, death, or December 31, 2022. A positive diagnosis of SARS-CoV-2 infection was determined through laboratory testing employing real-time reverse transcription polymerase chain reaction assays using nasopharyngeal or oropharyngeal swabs. The primary and secondary outcomes were HL and SSNHL, respectively. Age, sex, household income, Charlson comorbidity index, COVID-19 vaccination, hypertension, diabetes, and dyslipidemia-adjusted subdistribution hazard ratios (aSHRs) and 95% confidence intervals (CIs) were evaluated using the Fine-Gray subdistribution hazard regression model, considering overall death as a competing event to compare the aSHRs between COVID-19 positive and negative groups.
UNASSIGNED: A total of 6,716,879 young adults were eligible for the analyses. During 40,260,757 person-months (PMs) of follow-up, 38,269 cases of HL and 5908 cases of SSNHL were identified. The risk of HL (incidence: 11.9 versus 3.4/10,000 PMs; SHR, 3.51; 95% CI, 3.39-3.63; aSHR, 3.44; 95% CI, 3.33-3.56; P < 0.0001) and SSNHL (incidence: 1.8 versus 0.5/10,000 PMs; SHR, 3.58; 95% CI, 3.29-3.90; aSHR, 3.52; 95% CI, 3.23-3.83; P < 0.0001) was higher in COVID-19 group as compared to no COVID-19 group. In the sensitivity analyses that evaluated HL and SSNHL risks after adopting multiple imputations, utilizing inverse probability of treatment weighting, limiting study population to the cohort with a health screening examination, the results were consistent to the primary analysis.
UNASSIGNED: Our findings suggest a heightened risk of HL and SSNHL following COVID-19 in young adults. Due to study limitations, including the lack of objective audiological data, issues with generalizability to other populations, and the retrospective design, careful interpretation is necessary. Further studies with objective audiological data and a longer follow-up period are warranted.
UNASSIGNED: IITP (Institute for Information & Communications Technology Planning & Evaluation; IITP-2024- RS-00156439) and Jeju National University Hospital Research Fund (2023).

UNASSIGNED: To investigate the sex-specific association between habitual snoring and overall cancer prevalence and subtypes, and to examine the influence of age, body mass index (BMI), and sleep duration on this association.
UNASSIGNED: This study utilized data from the National Health and Nutrition Examination Survey cycles between 2005 and 2020 and included 15 892 participants aged 18 and over. We employed inverse probability of treatment weighting based on propensity scores to adjust for confounders when comparing the prevalence of cancer between habitual snorers and non-habitual snorers for each sex and cancer type. Subgroup analyses were conducted based on sleep duration, age, and BMI categories.
UNASSIGNED: The cohort (mean age 48.2 years, 50.4% female, and 30.5% habitual snorers) reported 1385 cancer cases. In men, habitual snoring was linked to 26% lower odds of any cancer (OR 0.74, 95% CI: 0.66 to 0.83), while in women, it showed no significant difference except lower odds of breast cancer (OR 0.77, 95% CI: 0.63 to 0.94) and higher odds of cervix cancer (OR 1.54, 95% CI: 1.18 to 2.01). Age and sleep duration significantly influenced the snoring-cancer relationship, with notable variations by cancer type and sex.
UNASSIGNED: Habitual snoring exhibits sex-specific associations with cancer prevalence, showing lower prevalence in men and varied results in women. These findings emphasize the critical need for further research to uncover the biological mechanisms involved. Future investigations should consider integrating sleep characteristics with cancer prevention and screening strategies, focusing on longitudinal research and the integration of genetic and biomarker analyses to fully understand these complex relationships.

BACKGROUND: MAGNITUDE (NCT03748641) demonstrated favourable outcomes with niraparib plus abiraterone acetate plus prednisone (+AAP) versus placebo+AAP in patients with BRCA1/2-altered metastatic castration-resistant prostate cancer (mCRPC). Imbalances in prognostic variables were reported between arms, which impacts estimation of both the clinical benefit and cost‑effectiveness of niraparib+AAP for healthcare systems. A pre-specified multivariable analysis (MVA) demonstrated improved overall survival (OS) with niraparib+AAP. Here, we used an inverse probability of treatment weighting (IPTW) model to adjust for covariate imbalances and assess time-to-event outcomes.
METHODS: IPTW analysis of time-to-event outcomes was conducted using data from patients with BRCA1/2-altered mCRPC (N = 225) in MAGNITUDE. Patients received niraparib+AAP or placebo+AAP. OS, radiographic progression-free survival, time to symptomatic progression, time to initiation of cytotoxic chemotherapy and time to prostate-specific antigen progression were assessed. Weighted Kaplan-Meier curves were generated for each endpoint, and adjusted hazard ratios (HR) were obtained from a weighted Cox model.
RESULTS: Improvements in survival outcomes were estimated for niraparib+AAP versus placebo+AAP: unadjusted median OS was 30.4 months versus 28.6 months, respectively (HR: 0.79; 95 % confidence interval [CI]: 0.55, 1.12; p = 0.183). Following IPTW, median OS increased to 34.1 months with niraparib+AAP versus a decrease to 27.4 with placebo (HR: 0.65; 95 % CI: 0.46, 0.93; p = 0.017). Similar improvements were observed for other time-to-event endpoints.
CONCLUSIONS: IPTW adjustment provided a more precise estimate of the clinical benefit of niraparib+AAP versus placebo+AAP in patients with BRCA1/2-altered mCRPC. Results were consistent with the pre-specified MVA, and further demonstrated the value of adjusting for baseline imbalances, particularly in smaller studies.
BACKGROUND: NCT03748641 (MAGNITUDE).

Marginal structural models have been increasingly used by analysts in recent years to account for confounding bias in studies with time-varying treatments. The parameters of these models are often estimated using inverse probability of treatment weighting. To ensure that the estimated weights adequately control confounding, it is possible to check for residual imbalance between treatment groups in the weighted data. Several balance metrics have been developed and compared in the cross-sectional case but have not yet been evaluated and compared in longitudinal studies with time-varying treatment. We have first extended the definition of several balance metrics to the case of a time-varying treatment, with or without censoring. We then compared the performance of these balance metrics in a simulation study by assessing the strength of the association between their estimated level of imbalance and bias. We found that the Mahalanobis balance performed best. Finally, the method was illustrated for estimating the cumulative effect of statins exposure over one year on the risk of cardiovascular disease or death in people aged 65 and over in population-wide administrative data. This illustration confirms the feasibility of employing our proposed metrics in large databases with multiple time-points.

Recently, it has become common for applied works to combine commonly used survival analysis modeling methods, such as the multivariable Cox model and propensity score weighting, with the intention of forming a doubly robust estimator of an exposure effect hazard ratio that is unbiased in large samples when either the Cox model or the propensity score model is correctly specified. This combination does not, in general, produce a doubly robust estimator, even after regression standardization, when there is truly a causal effect. We demonstrate via simulation this lack of double robustness for the semiparametric Cox model, the Weibull proportional hazards model, and a simple proportional hazards flexible parametric model, with both the latter models fit via maximum likelihood. We provide a novel proof that the combination of propensity score weighting and a proportional hazards survival model, fit either via full or partial likelihood, is consistent under the null of no causal effect of the exposure on the outcome under particular censoring mechanisms if either the propensity score or the outcome model is correctly specified and contains all confounders. Given our results suggesting that double robustness only exists under the null, we outline 2 simple alternative estimators that are doubly robust for the survival difference at a given time point (in the above sense), provided the censoring mechanism can be correctly modeled, and one doubly robust method of estimation for the full survival curve. We provide R code to use these estimators for estimation and inference in the supporting information.

UNASSIGNED: To observe the effect of Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) on the prognosis and the incidence of lymphatic leakage in patients undergoing radical cystectomy (RC).
UNASSIGNED: A total of 129 patients who underwent RC in Lanzhou University Second Hospital from 2013 to 2022 were enrolled in this study. They were divided into 43 patients treated with PA-MSHA and 86 patients in the control group. Inverse probability of treatment weighting (IPTW) was applied to reduce potential selection bias. Kaplan-Meier method and Cox regression analysis were used to analyze the effect of PA-MSHA on the survival of patients and the incidence of postoperative lymphatic leakage.
UNASSIGNED: The PA-MSHA group exhibited improved overall survival (OS) and cancer-specific survival (CSS) rates compared to the control group. The 3-year and 5-year overall survival (OS) rates for the PA-MSHA group were 69.1% and 53.2%, respectively, compared to 55.6% and 45.3% for the control group (Log-rank=3.218, P=0.072). The 3-year and 5-year cancer-specific survival (CSS) rates for the PA-MSHA group were 73.3% and 56.5%, respectively, compared to 58.0% and 47.3% for the control group (Log-rank=3.218, P=0.072). Additionally, the 3-year and 5-year progression-free survival (PFS) rates for the PA-MSHA group were 74.4% and 56.8%, respectively, compared to 57.1% and 52.2% for the control group (Log-rank=2.016, P=0.156). Multivariate Cox regression analysis indicates that lymph node metastasis and distant metastasis are poor prognostic factors for patients, while the use of PA-MSHA can improve patients\' OS (HR: 0.547, 95%CI: 0.304-0.983, P=0.044), PFS (HR: 0.469, 95%CI: 0.229-0.959, P=0.038) and CSS (HR: 0.484, 95%CI: 0.257-0.908, P=0.024). The same trend was observed in the cohort After IPTW adjustment. Although there was no significant difference in the incidence of postoperative lymphatic leakage [18.6% (8/35) vs. 15.1% (84.9%), P=0.613] and pelvic drainage volume [470 (440) ml vs. 462.5 (430) ml, P=0.814] between PA-MSHA group and control group, PA-MSHA could shorten the median retention time of drainage tube (7.0 d vs 9.0 d) (P=0.021).
UNASSIGNED: PA-MSHA may improve radical cystectomy in patients with OS, PFS, and CSS, shorten the pelvic drainage tube retention time.

OBJECTIVE: Although intrapleural administration of fibrinolytics is an important treatment option for the management of empyema, the addition of fibrinolytics failed to reduce the need for surgery and mortality in previous randomized controlled trials. This study aimed to investigate the effects of administrating fibrinolytics in the early phase (within 3 days of chest tube insertion) of empyema compared with late administration or no administration.
METHODS: We used the Japanese Diagnosis Procedure Combination Inpatient Database to identify patients aged ≥16 years who were hospitalized and underwent chest tube drainage for empyema. A 1:2 propensity score matching and stabilized inverse probability of treatment weighting were conducted.
RESULTS: Among the 16 265 eligible patients, 3082 and 13 183 patients were categorized into the early and control group, respectively. The proportion of patients who underwent surgery was significantly lower in the early fibrinolytics group than in the control group; the odds ratio (95% confidence interval) was 0.69 (0.54-0.88) in the propensity score matching (P = 0.003) and 0.64 (0.50-0.80) in the stabilized inverse probability of treatment weighting analysis (P < 0.001). All-cause 30-day in-hospital mortality, length of hospital stay, duration of chest tube drainage, and total hospitalization costs were also more favourable in the early fibrinolytics group.
CONCLUSIONS: The early administration of fibrinolytics may reduce the need for surgery and death in adult patients with empyema.

This study aimed to explore whether differences exist in anesthesia care providers\' use of intraoperative medication between African American and non-Hispanic White patients in adult surgical patients who underwent noncardiothoracic nonobstetric surgeries with general anesthesia. A retrospective observational cohort study used electronic health records between January 1, 2018 and August 31, 2019 at a large academic health system in the southeastern United States. To evaluate the isolated impact of race on intraoperative medication use, inverse probability of treatment weighting using the propensity scores was used to balance the covariates between African American and non-Hispanic White patients. Regression analyses were then performed to evaluate the impact of race on the total dose of opioid analgesia administered, and the use of midazolam, sugammadex, antihypotensive drugs, and antihypertensive drugs. Of the 31,790 patients included in the sample, 58.9% were non-Hispanic Whites and 13.6% were African American patients. After adjusting for significant covariates, African American patients were more likely to receive midazolam premedication (p < .0001; adjusted odds ratio [aOR] = 1.17, 99.9% CI [1.06, 1.30]), and antihypertensive drugs (p = .0002; aOR = 1.15, 99.9% CI [1.02, 1.30]), and less likely to receive antihypotensive drugs (p < .0001; aOR = 0.85, 99.9% CI [0.76, 0.95]) than non-Hispanic White patients. However, we did not find significant differences in the total dose of opioid analgesia administered, or sugammadex. This study identified differences in intraoperative anesthesia care delivery between African American and non-Hispanic White patients; however, future research is needed to understand mechanisms that contribute to these differences and whether these differences are associated with patient outcomes.