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HeadPoST

Cluster-Randomized, Crossover Trial of Head Positioning in Acute Stroke

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Year of Publication: 2017

Authors: Anderson CS, Arima H, Lavados P, et al. (HeadPoST Investigators and Coordinators)

Journal: NEJM

Citation: N Engl J Med 2017;376:2437–2447. DOI: 10.1056/NEJMoa1615715

Link: https://doi.org/10.1056/NEJMoa1615715

Bottom Line

Head positioning (lying-flat vs sitting-up ≥30°) initiated a median of 14 hours after acute stroke onset and maintained for 24 hours did not alter 90-day disability, mortality, or pneumonia risk.

        Major Points
        Pragmatic international cluster-randomized crossover trial at 114 hospitals in 9 countries randomized 11,093 acute-stroke patients (5,295 lying-flat vs 5,798 sitting-up) to a head position initiated soon after admission and maintained for 24 hours.
Primary outcome (90-day disability on modified Rankin scale) showed no difference: unadjusted OR 1.01 (95% CI 0.92–1.10), P=0.84; adjusted analyses and analyses restricted to ischemic stroke or ICH gave the same result.
Death or major disability (mRS 3–6) at 90 days: 38.9% vs 39.7% (OR 0.94, 95% CI 0.85–1.05, P=0.25); 90-day mortality 7.3% vs 7.4% (OR 0.98, 95% CI 0.85–1.14, P=0.83).
Serious adverse events (14.3% vs 13.5%, P=0.51), including pneumonia, did not differ; the sitting-up group achieved better position adherence (95% vs 87% maintained for 24 hours, P<0.001).
Findings were consistent across prespecified subgroups (age, sex, region, baseline NIHSS, time from onset, stroke subtype, randomization sequence); most patients were enrolled well beyond the reperfusion window with mostly mild strokes (median NIHSS 4).

      

Design

Study Type: Pragmatic, cluster-randomized, crossover, open-label trial with blinded outcome assessment

Randomization: 1

Blinding: Open-label intervention; outcome assessors blinded (PROBE-style)

Enrollment Period: March 2, 2015 – November 29, 2016

Follow-up Duration: 90 days

Centers: 114

Countries: Australia, China, Taiwan, India, Sri Lanka, United Kingdom, Chile, Brazil, Colombia

Sample Size: 11093

Analysis: Intention-to-treat, ordinal logistic-regression mixed model with fixed intervention and period effects, random cluster effect, and cluster × period interaction; multiple imputation for missing mRS

Inclusion Criteria

Age ≥18 years
Clinical diagnosis of acute stroke (ischemic or intracerebral hemorrhage)
Presentation to emergency department or inpatient service at a participating hospital
Patients with acute intracerebral hemorrhage (but not subarachnoid hemorrhage) purposely included
Ability to assume the assigned head position soon after admission

Exclusion Criteria

Confirmed diagnosis of transient ischemic attack
Clear clinical indication for, or contraindication to, either head position (e.g., patients likely requiring intubation)
Local clinician-investigator judged the assigned head position could not be consistently maintained
Subarachnoid hemorrhage
Patient declined participation

Baseline Characteristics

Overall (both arms similar):

N: 11,093 (5,295 lying-flat; 5,798 sitting-up)
Mean Age: 68 years
Age ≥80 years: 23%
Sex - Female: 40%
Acute Ischemic Stroke: 85%
Acute Intracerebral Hemorrhage: ≈13%
Median Baseline NIHSS: 4 (IQR 2–8)
Median Time from Stroke Onset to Position Initiation: 14 hours (IQR 5–35)
Median Time from Hospital Presentation to Position Initiation: 7 hours (IQR 2–26–27)

Arms

Field	Lying-flat	Control
Intervention	Fully supine (back horizontal, face upwards), initiated soon after admission and maintained for 24 hours, including during eating, drinking, and toileting	Head of bed elevated to ≥30° (confirmed by protractor), maintained for 24 hours; toilet privileges outside bed permitted per mobility
Duration	24 hours	24 hours

Outcomes

Outcome	Type	Control	Intervention	HR / OR / RR	P-value
Shift in distribution of 90-day disability on the modified Rankin scale (mRS 0–6), analyzed by ordinal logistic regression	Primary	Sitting-up mRS distribution (reference)	Lying-flat mRS distribution	1.01	0.84
Death or major disability (mRS 3–6) at 90 days	Secondary	39.7%	38.9%	0.94	0.25
All-cause death within 90 days	Secondary	7.4%	7.3%	0.98	0.83
EQ-5D visual-analogue self-rated health at 90 days	Secondary	reference	favored lying-flat		0.009
Position adherence (maintained assigned position for 24 h)	Secondary	95%	87%		<0.001
Premature cessation of assigned position within 24 h	Secondary	4.2%	13.0%		<0.001
mRS distribution at 7 days / NIHSS categorical scores at 7 days	Secondary	reference	no significant difference		NS
Serious adverse events (any)	Adverse	Lying-flat 14.3% vs Sitting-up 13.5% (P=0.51)
Pneumonia	Adverse	No significant between-group difference
Cardiopulmonary adverse events / oxygen saturation / blood pressure	Adverse	No significant between-group differences

Subgroup Analysis

No significant heterogeneity in the primary outcome across prespecified subgroups defined by age, sex, country/region grouping, baseline NIHSS, time from stroke onset to intervention, major pathologic subtype (ischemic vs ICH), or hospital randomization sequence. Post-hoc analyses by NIHSS quintile and by time-to-intervention quintile also showed no heterogeneity.

Criticisms

Median 14 hours from stroke onset to positioning meant most patients were past the reperfusion window and any effect of positioning on the ischemic penumbra would be minimal.
Mostly mild strokes (median baseline NIHSS 4), limiting the ability to detect a benefit that might exist in more severe or large-vessel occlusion strokes.
Cluster-randomized crossover design with unavoidable open-label intervention; adherence to the lying-flat position was significantly lower (87% vs 95%), potentially diluting a true effect.
Target sample size (12,000) not reached; power reestimated using observed intracluster (0.083) and interperiod (0.076) correlations, but subgroup analyses remained underpowered.
Included acute intracerebral hemorrhage in a stroke-positioning trial, which mixes pathophysiologies; separate analyses by subtype were nonetheless consistent with the primary result.
Enrollment concentrated in centers largely outside the acute reperfusion era limits generalizability to modern thrombolysis/thrombectomy workflows.

Funding

National Health and Medical Research Council of Australia (research grant 1066966); coordinated by the George Institute for Global Health.

Based on: HeadPoST (NEJM, 2017)

Authors: Anderson CS, Arima H, Lavados P, et al. (HeadPoST Investigators and Coordinators)

Citation: N Engl J Med 2017;376:2437–2447. DOI: 10.1056/NEJMoa1615715

Content summarized and formatted by NeuroTrials.ai.

HeadPoST

(2017)

Objective

Determine whether lying-flat vs sitting-up head positioning for 24 hours after acute stroke reduces 90-day disability.

Study Summary

• No significant difference in 90-day disability distribution on modified Rankin scale: unadjusted OR 1.01 (95% CI 0.92–1.10), P=0.84.
• 90-day mortality was 7.3% (lying-flat) vs 7.4% (sitting-up), OR 0.98 (0.85–1.14), P=0.83.
• No difference in serious adverse events (14.3% vs 13.5%, P=0.51), including pneumonia.

Intervention

Lying-flat (fully supine) vs sitting-up (head elevated ≥30°) position initiated soon after admission and maintained for 24 hours.

Inclusion Criteria

Adults ≥18 years with clinical diagnosis of acute stroke (ischemic or intracerebral hemorrhage) presenting to emergency department or inpatient service at a participating center.

Study Design

Arms: Lying-flat position vs sitting-up position with head elevated ≥30° for 24 hours

Patients per Arm: 5,295 lying-flat vs 5,798 sitting-up (total 11,093)

Outcome

• Primary (90-day mRS shift): OR 1.01 (95% CI 0.92–1.10), P=0.84 – no benefit.
• Death or major disability (mRS 3–6) at 90 days: 38.9% vs 39.7%, OR 0.94 (0.85–1.05), P=0.25.
• Pneumonia and other serious AEs did not differ between groups; results consistent across prespecified subgroups (age, sex, stroke type, NIHSS, time to intervention).

Clinical Question

In patients with acute stroke, does a lying-flat head position for 24 hours improve 90-day disability compared with a sitting-up position (head elevated ≥30°)?

Bottom Line

Head positioning (lying-flat vs sitting-up ≥30°) initiated a median of 14 hours after acute stroke onset and maintained for 24 hours did not alter 90-day disability, mortality, or pneumonia risk.

Major Points

Pragmatic international cluster-randomized crossover trial at 114 hospitals in 9 countries randomized 11,093 acute-stroke patients (5,295 lying-flat vs 5,798 sitting-up) to a head position initiated soon after admission and maintained for 24 hours.
Primary outcome (90-day disability on modified Rankin scale) showed no difference: unadjusted OR 1.01 (95% CI 0.92–1.10), P=0.84; adjusted analyses and analyses restricted to ischemic stroke or ICH gave the same result.
Death or major disability (mRS 3–6) at 90 days: 38.9% vs 39.7% (OR 0.94, 95% CI 0.85–1.05, P=0.25); 90-day mortality 7.3% vs 7.4% (OR 0.98, 95% CI 0.85–1.14, P=0.83).
Serious adverse events (14.3% vs 13.5%, P=0.51), including pneumonia, did not differ; the sitting-up group achieved better position adherence (95% vs 87% maintained for 24 hours, P<0.001).
Findings were consistent across prespecified subgroups (age, sex, region, baseline NIHSS, time from onset, stroke subtype, randomization sequence); most patients were enrolled well beyond the reperfusion window with mostly mild strokes (median NIHSS 4).

Study Design

Study Type: Pragmatic, cluster-randomized, crossover, open-label trial with blinded outcome assessment
Randomization: Yes
Blinding: Open-label intervention; outcome assessors blinded (PROBE-style)
Sample Size: 11093
Follow-up: 90 days
Centers: 114
Countries: Australia, China, Taiwan, India, Sri Lanka, United Kingdom, Chile, Brazil, Colombia

Primary Outcome

Definition: Shift in distribution of 90-day disability on the modified Rankin scale (mRS 0–6), analyzed by ordinal logistic regression

Control	Intervention	HR/OR	P-value
Sitting-up mRS distribution (reference)	Lying-flat mRS distribution	1.01 (0.92–1.10)	0.84

Limitations & Criticisms

Median 14 hours from stroke onset to positioning meant most patients were past the reperfusion window and any effect of positioning on the ischemic penumbra would be minimal.
Mostly mild strokes (median baseline NIHSS 4), limiting the ability to detect a benefit that might exist in more severe or large-vessel occlusion strokes.
Cluster-randomized crossover design with unavoidable open-label intervention; adherence to the lying-flat position was significantly lower (87% vs 95%), potentially diluting a true effect.
Target sample size (12,000) not reached; power reestimated using observed intracluster (0.083) and interperiod (0.076) correlations, but subgroup analyses remained underpowered.
Included acute intracerebral hemorrhage in a stroke-positioning trial, which mixes pathophysiologies; separate analyses by subtype were nonetheless consistent with the primary result.
Enrollment concentrated in centers largely outside the acute reperfusion era limits generalizability to modern thrombolysis/thrombectomy workflows.

Citation

N Engl J Med 2017;376:2437–2447. DOI: 10.1056/NEJMoa1615715

View Original Publication →

HeadPoST

Cluster-Randomized, Crossover Trial of Head Positioning in Acute Stroke

Bottom Line

Major Points

Design

Inclusion Criteria

Exclusion Criteria

Baseline Characteristics

Arms

Outcomes

Subgroup Analysis

Criticisms

Funding

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