An interventional study of body position in Blood Pressure Measurement, sponsored by Iuliu Hatieganu University of Medicine and Pharmacy. Not yet recruiting at 2 sites in Romania. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by Iuliu Hatieganu University of Medicine and Pharmacy · Not applicable, Interventional, and Other
Blood pressure is an important part of checking heart health. Blood pressure is usually measured while sitting, but in everyday medical care it is sometimes measured in other positions, such as the Fowler position, where the upper body is raised. This study will compare blood pressure measured while sitting with blood pressure measured in the Fowler position to see whether the results are similar enough to be considered equivalent. Adults aged 18 or older who can give informed consent and have an arm circumference of 22-42 cm may take part. Each participant will have their blood pressure measured in both positions, with the order chosen randomly. People who cannot maintain the required positions or whose condition could affect the accuracy of the blood pressure measurement will not take part.
Background and Rationale Blood pressure (BP) measurement is a cornerstone of cardiovascular assessment. Standard guidelines recommend seated BP measurements; however, in routine clinical practice, measurements are frequently obtained in alternative positions such as the Fowler position. This study aims to determine whether SBP measurements obtained in the Fowler position are clinically equivalent to those obtained in the seated position.
Objectives The primary objective is to determine whether SBP measured in the Fowler position is equivalent to SBP measured in the seated position within a predefined clinical equivalence margin of ±5 mmHg.
Hypothesis Null hypothesis: The mean paired difference in SBP between Fowler and seated positions is outside the equivalence margin of ±5 mmHg.
Alternative hypothesis: The mean paired difference in SBP between Fowler and seated positions lies within the equivalence margin of ±5 mmHg.
Study Design This is a prospective, randomized, paired equivalence trial. Each participant will undergo SBP measurement in both seated and Fowler positions, with the order of positions randomized.
Setting Outpatient cardiology clinic. Blood Pressure Measurement Protocol Blood pressure will be measured using a validated automated OMRON device. For each position, three consecutive (1 minute apart) SBP measurements will be obtained and averaged. A rest period of 5 minutes will be observed after changing position before measurements, with a 5-minute rest period before the first BP measurement. The same arm and appropriately sized cuff will be used for all measurements.
Seated position
Randomization Participants will be randomized 1:1 to one of two measurement sequences: (1) seated first followed by Fowler, or (2) Fowler first followed by seated. The method used is random block generation, to account for the relatively small size of the study population.
Outcome Measure Primary outcome: Mean paired difference in systolic blood pressure between Fowler and seated positions.
Sample Size Calculation Assuming a standard deviation of paired differences of 9 mmHg, an equivalence margin of ±5 mmHg, a two-sided alpha of 0.01, and 95% power, a minimum of 120 participants is required. This will yield 240 observations between the two positions.
Statistical Analysis Analyses will be performed according to a per-protocol principle, as recommended for equivalence trials.
The mean paired difference (Fowler - seated, seated - Fowler) will be calculated for each participant.
Equivalence will be assessed using the TOST procedure. A 99% confidence interval (CI) for the mean paired SBP difference will be constructed. Equivalence will be concluded if the entire CI lies within the predefined equivalence margin of ±5 mmHg.
Normality of paired differences will be evaluated using the Shapiro-Wilk test. If violated, bootstrap confidence intervals (10,000 resamples) will be used.
All tests will be two-sided with significance level α = 0.01. Ethical Considerations The study will be conducted in accordance with the Declaration of Helsinki. All participants will provide written informed consent prior to participation.
Data Management Data will be collected anonymously and stored securely. Only study investigators will have access to the final dataset.
Iuliu Hatieganu University of Medicine and Pharmacy is the lead sponsor of 55 studies on the registry; 14 are open to participants now.
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Exclusion Criteria:
standardised BP measurement
Other: body position
BP measurement in the fowler position
Other: body position
Body position relevance for the assessment of blood pressure
Mean paired difference in systolic blood pressure
Primary outcome: Mean paired difference in systolic blood pressure between Fowler and seated positions.
Time frame: 25-30 minutes
Plan to share: Yes — BP measurements, Demographic data, Medical History, and further data, on reasonable request
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
Time frame: dec 2026- dec 2027
Access criteria: by direct request, any scientific research personnel
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Iuliu Hatieganu University of Medicine and Pharmacy