The wicked path of causal inference in observational studies

Association Between Incident Delirium Treatment With Haloperidol and Mortality in Critically Ill Adults

OBJECTIVES

Haloperidol is commonly administered in the ICU to reduce the burden of delirium and its related symptoms despite no clear evidence showing haloperidol helps to resolve delirium or improve survival. We evaluated the association between haloperidol, when used to treat incident ICU delirium and its symptoms, and mortality.

DESIGN

Post hoc cohort analysis of a randomized, double-blind, placebo-controlled, delirium prevention trial.

SETTING

Fourteen Dutch ICUs between July 2013 and December 2016.

PATIENTS

One-thousand four-hundred ninety-five critically ill adults free from delirium at ICU admission having an expected ICU stay greater than or equal to 2 days.

INTERVENTIONS

Patients received preventive haloperidol or placebo for up to 28 days until delirium occurrence, death, or ICU discharge. If delirium occurred, treatment with open-label IV haloperidol 2 mg tid (up to 5 mg tid per delirium symptoms) was administered at clinician discretion.

MEASUREMENTS AND MAIN RESULTS

Patients were evaluated tid for delirium and coma for 28 days. Time-varying Cox hazards models were constructed for 28-day and 90-day mortality, controlling for study-arm, delirium and coma days, age, Acute Physiology and Chronic Health Evaluation-II score, sepsis, mechanical ventilation, and ICU length of stay. Among the 1,495 patients, 542 (36%) developed delirium within 28 days (median [interquartile range] with delirium 4 d [2-7 d]). A total of 477 of 542 (88%) received treatment haloperidol (2.1 mg [1.0-3.8 mg] daily) for 6 days (3-11 d). Each milligram of treatment haloperidol administered daily was associated with decreased mortality at 28 days (hazard ratio, 0.93; 95% CI, 0.91-0.95) and 90 days (hazard ratio, 0.97; 95% CI, 0.96-0.98). Treatment haloperidol administered later in the ICU course was less protective of death. Results were stable by prevention study-arm, predelirium haloperidol exposure, and haloperidol treatment protocol adherence.

CONCLUSIONS

Treatment of incident delirium and its symptoms with haloperidol may be associated with a dose-dependent improvement in survival. Future randomized trials need to confirm these results.

Systematic review with meta-analysis: limited benefits from early colonoscopy in acute lower gastrointestinal bleeding

BACKGROUND

The optimal timing of colonoscopy in acute lower gastrointestinal bleeding (LGIB) remains controversial.

AIM

To characterise the utility of early colonoscopy (within 24 hours) in managing acute LGIB.

METHODS

A systematic literature search to October 2019 identified fully published articles and abstracts of randomised controlled trials (RCTs) and observational studies with control groups assessing early colonoscopy in acute LGIB. The primary outcome was rebleeding. Secondary outcomes included mortality, surgery, length of stay (LOS), definite cause of bleeding and adverse events. Odds ratios (ORs) and mean differences (MD) were calculated.

RESULTS

Of 1116 citations, 4 RCTs (466 patients) and 13 observational studies with elective colonoscopy (>24 hours) as control group (1 061 281 patients) were included. No differences in rebleeding were noted between early and elective colonoscopy groups among RCTs alone (OR = 1.70; 0.79; 3.64), or observational studies alone (OR = 1.20; 0.69; 2.09). No other significant between-group differences in outcomes were found when restricting the analysis to RCTs. Among observational studies only, early colonoscopy was associated with lower rates of all-cause mortality (OR = 0.86; 0.75; 0.98), surgery (OR = 0.52; 0.42; 0.64), blood transfusion (OR = 0.81; 0.75; 0.87), units of blood transfusion (MD = -4.30; -6.24; -2.36) and shorter LOS (MD = -1.70; -1.70; -1.70 days).

CONCLUSION

In contradistinction to observational studies, data from RCTs do not support a role for early colonoscopy in the routine management of acute LGIB with regards to the most important clinical outcomes. Further research is needed to better identify patients with high-risk LGIB who may benefit from early colonoscopy.