Analysis of causality from observational studies and its application in clinical research in Intensive Care Medicine

Two-row, three-row or powered circular stapler, which to choose when performing colorectal anastomosis? A systematic review and meta-analysis

PURPOSE

Three types of circular staplers can be used to perform a colorectal anastomosis: two-row (MCS), three-row (TRCS) and powered (PCS) devices. The objective of this meta-analysis has been to provide the existing evidence on which of these circular staplers would have a lower risk of presenting a leak (AL) and/or anastomotic bleeding (AB).

METHODS

An in-depth search was carried out in the electronic bibliographic databases Embase, PubMed and SCOPUS. Observational studies were included, since randomized clinical trials comparing circular staplers were not found.

RESULTS

In the case of AL, seven studies met the inclusion criteria in the PCS group and four in the TRCS group. In the case of AB, only four studies could be included in the analysis in the PCS group. The AL OR reported for PCS was 0.402 (95%-confidence interval (95%-CI): 0.266-0.608) and for AB: 0.2 (95% CI: 0.08-0.52). The OR obtained for AL in TRCS was 0.446 (95%-CI: 0.217 to 0.916). Risk difference for AL in PCS was - 0.06 (95% CI: - 0.07 to - 0.04) and in TRCS was - 0.04 (95%-CI: - 0.08 to - 0.01). Subgroup analysis did not report significant differences between groups. On the other hand, the AB OR obtained for PCS was 0.2 (95% CI: 0.08-0.52). In this case, no significant differences were observed in subgroup analysis.

CONCLUSION

PCS presented a significantly lower risk of leakage and anastomotic bleeding while TRCS only demonstrated a risk reduction in AL. Risk difference of AL was superior in the PCS than in TRCS.

Atrial Fibrillation in Critically Ill Patients: Incidence and Outcomes

BACKGROUND

Atrial fibrillation (AF), either chronic or new onset, is common in critically ill patients. Its epidemiology and relationship with clinical outcomes are poorly known.

OBJECTIVE

To understand the burden of AF in patients admitted to the ICU and its impact on patients' outcomes.

METHODS

This is a single-center, retrospective cohort study evaluating all patients with AF admitted to a non-cardiac intensive care unit over the course of 54 months. Clinical outcomes were evaluated in the short (hospital discharge) and long term (two-year follow-up). The hazard ratio (HR) with 95% CI was computed for the whole population as well as for propensity score-matched patients, with or without AF.

RESULTS

A total of 1357 patients were screened (59.1% male), with a mean age of 75 ± 15.2 years, length of intensive care unit stay of 4.7 ± 5.1 days, and hospital mortality of 26%. A diagnosis of AF was found in 215 patients (15.8%), 142 of whom had chronic AF. The hospital all-cause mortality was similar in patients with chronic or new-onset AF (31% vs. 28.8%, p = 0.779). Patients with AF had higher in-hospital, one-year, and two-year crude mortality (30.2% vs. 22.9%, p = 0.024; 47.9% vs. 35.3%, p = 0.001; 52.6% vs. 38.4%, p < 0.001). However, after propensity score matching (N = 213), this difference was no longer significant for in-hospital mortality (OR: 1.17; 95% CI: 0.77-1.79), one-year mortality (OR: 1.38; 95% CI: 0.94-2.03), or two-year mortality (OR: 1.30; 95% CI: 0.89-1.90).

CONCLUSIONS

In ICU patients, the prevalence of AF, either chronic or new-onset, was 15.8%, and these patients had higher crude mortality. However, after adjustment for age and severity on admission, no significant differences were found in the short- and long-term mortality.

Critically ill patients with high predicted mortality: Incidence and outcome

OBJECTIVE

As calculated by the severity scores, an unknown number of patients are admitted to the Intensive Care Unit (ICU) with a very high risk of death. Clinical studies have poorly addressed this population, and their prognosis is largely unknown.

DESIGN

Post hoc analysis of a multicenter, cohort, longitudinal, observational, retrospective study (CIMbA).

SETTING

Sixteen Portuguese multipurpose ICUs.

PATIENTS

Patients with a Simplified Acute Physiology Score II (SAPS II) predicted hospital mortality above 80% on admission to the ICU (high-risk group); A comparison with the remaining patients was obtained.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

Hospital, 30 days, 1 year mortality.

RESULTS

We identified 4546 patients (59.9% male), 12.2% of the whole population. Their SAPS II predicted hospital mortality was 89.0±5.8%, whilst the observed mortality was lower, 61.0%. This group had higher mortality, both during the first 30 days (aHR 3.52 [95% CI 3.34-3.71]) and from day 31 to day 365 after ICU admission (aHR 1.14 [95%CI 1.04-1.26]), respectively. However, their hospital standardized mortality ratio was similar to the other patients (0.69 vs. 0.69, P=.92). At one year of follow-up, 30% of patients in the high-risk group were alive.

CONCLUSIONS

Roughly 12% of patients admitted to the ICU for more than 24h had a SAPS II score predicted mortality above 80%. Their hospital standardized mortality was similar to the less severe population and 30% were alive after one year of follow-up.

Triclosan-coated barbed sutures in elective laparoscopic colorectal cancer surgery: a propensity score matched cohort study

BACKGROUND

Most of the studies published to date which assess the role of antibacterial sutures in surgical site infection (SSI) prevention include heterogeneous groups of patients, and it is therefore difficult to draw conclusions. The objective of the present study was to investigate whether the use of Triclosan-coated barbed sutures (TCBS) was associated with a lower incidence of incisional SSI and lower duration of hospital stay compared to standard sutures, in elective laparoscopic colorectal cancer surgery.

METHOD

Observational including patients who underwent elective colorectal cancer laparoscopic surgery between January 2015 and December 2020. The patients were divided into two groups according to the suture used for fascial closure of the extraction incision, TCBS vs conventional non-coated sutures (CNCS), and the rate of SSI was analysed. The TCBS cases were matched to CNCS cases by propensity score matching to obtain comparable groups of patients.

RESULTS

488 patients met the inclusion criteria. After adjusting the patients with the propensity score, two new groups of patients were generated: 143 TCBS cases versus 143 CNCS cases. Overall incisional SSI appeared in 16 (5.6%) of the patients with a significant difference between groups depending on the type of suture used, 9.8% in the group of CNCS and 1.4% in the group of TCBS (OR 0.239 (CI 95%: 0.065-0.880)). Hospital stay was significantly shorter in TCBS group than in CNCS, 5 vs 6 days (p < 0.001).

CONCLUSION

TCBS was associated with a lower incidence of incisional SSI compared to standard sutures in a cohort of patients undergoing elective laparoscopic colorectal cancer surgery.

Matched cohort study on the efficacy of tocilizumab in patients with COVID-19

BACKGROUND

Tocilizumab has been proposed as a treatment for the new disease COVID-19, however, there is not enough scientific evidence to support this treatment. The objective of this study is to analyze whether the use of tocilizumab is associated with respiratory improvement and a shorter time to discharge in patients with COVID-19 and lung involvement.

METHODS

Observational study on a cohort of 418 patients, admitted to three county hospitals in Catalonia (Spain). Patients admitted consecutively were included and followed until discharge or up to 30 days of admission. A sub-cohort of patients treated with tocilizumab and a sub-cohort of control patients were identified, matched by a large number of risk factors and clinical variables. Sub-cohorts were also matched by the number of other treatments for COVID-19 that patients received. Increment in SAFI (inspired oxygen fraction / saturation) 48 h after the start of treatment, and time to discharge, were the primary outcomes. Mortality, which was a secondary outcome, was analyzed in the total cohort, by using logistic regression models, adjusted by confounders.

RESULTS

There were 96 patients treated with tocilizumab. Of them, 22 patients could be matched with an equivalent number of control patients. The increment in SAFI from baseline to 48 h of treatment, was not significantly different between groups (tocilizumab: -0.04; control: 0.09; p = 0.636). Also, no difference in time to discharge was found between the two sub-cohorts (logrank test: p = 0.472). The logistic regression models, did not show an effect of tocilizumab on mortality (OR 0.99; p = 0.990).

CONCLUSIONS

We did not find a clinical benefit associated with the use tocilizumab, in terms of respiratory function at 48 h of treatment, or time to discharge.

Autoimmune Diseases and COVID-19 as Risk Factors for Poor Outcomes: Data on 13,940 Hospitalized Patients from the Spanish Nationwide SEMI-COVID-19 Registry

(1) Objectives: To describe the clinical characteristics and clinical course of hospitalized patients with COVID-19 and autoimmune diseases (ADs) compared to the general population. (2) Methods: We used information available in the nationwide Spanish SEMI-COVID-19 Registry, which retrospectively compiles data from the first admission of adult patients with COVID-19. We selected all patients with ADs included in the registry and compared them to the remaining patients. The primary outcome was all-cause mortality during admission, readmission, and subsequent admissions, and secondary outcomes were a composite outcome including the need for intensive care unit (ICU) admission, invasive and non-invasive mechanical ventilation (MV), or death, as well as in-hospital complications. (3) Results: A total of 13,940 patients diagnosed with COVID-19 were included, of which 362 (2.6%) had an AD. Patients with ADs were older, more likely to be female, and had greater comorbidity. On the multivariate logistic regression analysis, which involved the inverse propensity score weighting method, AD as a whole was not associated with an increased risk of any of the outcome variables. Habitual treatment with corticosteroids (CSs), age, Barthel Index score, and comorbidity were associated with poor outcomes. Biological disease-modifying anti-rheumatic drugs (bDMARDs) were associated with a decrease in mortality in patients with AD. (4) Conclusions: The analysis of the SEMI-COVID-19 Registry shows that ADs do not lead to a different prognosis, measured by mortality, complications, or the composite outcome. Considered individually, it seems that some diseases entail a different prognosis than that of the general population. Immunosuppressive/immunoregulatory treatments (IST) prior to admission had variable effects.

Evaluation and closure of the series on methodology in Intensive Care Medicine

The series of updates on methodology for research in critically ill patients has addressed the difficulties caused by the characteristics of patients of this kind, bioethics, the interpretation of results, and methodological error. New statistical methods for causality research, meta-analysis and big data analysis have also been described. The last update refers to the horizon for new research in the field of critical care. We close the series with the hope of having provided a global vision of the statistical methods oriented toward the future, with the aim of promoting statistical culture. In parallel, we have analyzed the evolution in complexity of the methodological analysis in the journal.