Survival analysis is often used in studies of clinical epidemiology, but the existence of competing risks has not been adequately considered. Competing risks may hinder observation of the outcome of interest or modify the occurrence of the outcome. In the presence of competing risks, conventional survival analysis leads to biased results. To conduct a survival analysis in the presence of competing risks, researchers should select an appropriate method from the following two options: cause-specific hazard model and subdistribution hazard model. This article explains the issues raised by the presence of competing risks and describes methods to account for competing risks in survival analysis.

BACKGROUND

Cardiac surgery is a highly invasive procedure resulting in hypercoagulability due to thoracotomy and cardiopulmonary bypass (CPB). The long-term use of selective cyclooxygenase-2 inhibitors has been shown to increase the risk of adverse cardiovascular (CV) events such as myocardial infarction. This study aimed to determine whether short-term prescription of celecoxib increases CV events in patients who have undergone cardiac surgery with CPB.

METHODS

This retrospective observational study included 16,141 patients (≥20 years) who had undergone cardiac surgery with CPB between April 1, 2008 and March 31, 2016. Patients who underwent coronary artery bypass grafting were excluded. Patients who received celecoxib (n = 904) and acetaminophen (n = 5,002) from postoperative day 0 to 30 were extracted and matched by propensity score (PS). The primary outcomes were all-cause death and CV events, defined as coronary artery disease, ischemic stroke, pulmonary embolism, and venous thrombosis, coded using International Classification of Diseases-10 within 30 days after the first postoperative prescription of either medication. Results were assessed using Kaplan-Meier survival analysis and multivariate Cox regression analysis.

RESULTS

PS matching created 885 pairs. Multivariate Cox regression analysis showed that prescription of celecoxib after cardiac surgery was not associated with an increase in the primary outcomes when compared with prescription of acetaminophen (hazard ratio, 0.76; 95% confidence interval, 0.35–1.65).

CONCLUSIONS

The prescription of celecoxib in patients who had undergone cardiac surgery with cardiopulmonary bypass was not statistically different from the prescription of acetaminophen in the incidence of CV events and death.

BACKGROUND

The benefits of cataract surgery for patients aged ≥90 years in terms of improvements in activities of daily living (ADL) have been poorly evaluated using only limited data. Using a large nationwide administrative database of hospitalized patients, we investigated the improvement of ADL after cataract surgery in the very old (age of ≥90 years).

METHODS

We identified 84,747 patients with cataracts aged 80 to 89 years and 7,253 patients with cataracts aged ≥90 years who underwent cataract surgery in both eyes during hospitalization from April 2014 to March 2015. A retrospective matched-pair cohort study was performed to compare the proportion of patients with improved ADL after cataract surgery. We also compared the length of hospital stay between the two groups.

RESULTS

Patients aged ≥90 years were more likely to be female and have a lower ADL score at admission. In the 1:4 matched-pair analysis with 7,253 versus 29,012 pairs, a lower proportion of patients aged ≥90 years had an improved ADL score (odds ratio, 0.33; 95% confidence interval, 0.29–0.36; P < 0.001) even after adjusting for other variables. Patients aged ≥90 years had a slightly shorter length of hospital stay than those aged 80 to 89 years (7.5 vs. 8.2 days, respectively; P < 0.001).

CONCLUSIONS

In this large nationwide cohort of patients with cataracts, those aged ≥90 years showed significantly poorer improvement of ADL than did patients aged 80 to 89 years. Cataract surgery before the age of 90 years may be recommended for patients with cataracts.

BACKGROUND

Delirium is the most commonly experienced disorder in consultation liaisons. There are currently research and guidelines in Japan for delirium treatment. Still, there is no retrospective observational study of consultation-liaison psychiatry (CLP) and antipsychotic-centered drugs. This study aims to examine CLP’s effectiveness and drug treatment.

METHODS

Using a Japanese national inpatient database of 2016 and 2017, we investigated the presence or absence of CLP for the treatment of delirium in postoperative delirium patients, the status of drug selection, delirium days, and the average days from surgery to discharge. We examined factors affecting days from surgery to discharge using multiple linear regression analysis.

RESULTS

This study was classified into a CLP group (n = 1,142) and a non-CLP group (n = 11,355). The days from surgery to discharge in the CLP and non-CLP groups was 16.7 and 17.1, respectively (p = 0.3613). There was a significant difference in the delirium days between the CLP and non-CLP groups (8.9 vs. 7.4; p < 0.00001). Haloperidol infusion was frequently used between the days from surgery to first day of delirium. It was prescribed less often than other oral drugs. Multiple regression analysis identified an association between age, men, CCI1-2, CCI ≥3, number of drugs used, days from surgery to first day of delirium, and early CLP (0–2days) with days from surgery to discharge.

CONCLUSIONS

We investigated the effectiveness of CLP and the actual conditions of pharmacotherapy for postoperative delirium. Our findings suggest that early CLP may be associated with shorter days from surgery to discharge.