Attrition in longitudinal randomized controlled trials: home visits make a difference

<p>Abstract</p> <p>Background</p> <p>Participant attrition in longitudinal studies can introduce systematic bias, favoring participants who return for follow-up, and increase the likelihood that those with complications will be underestimated. Our aim was to examine the...

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Main Authors: Peterson Janey C, Pirraglia Paul A, Wells Martin T, Charlson Mary E
Format: Article
Language:English
Published: BMC 2012-11-01
Series:BMC Medical Research Methodology
Subjects:
Online Access:http://www.biomedcentral.com/1471-2288/12/178
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author Peterson Janey C
Pirraglia Paul A
Wells Martin T
Charlson Mary E
author_facet Peterson Janey C
Pirraglia Paul A
Wells Martin T
Charlson Mary E
author_sort Peterson Janey C
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Participant attrition in longitudinal studies can introduce systematic bias, favoring participants who return for follow-up, and increase the likelihood that those with complications will be underestimated. Our aim was to examine the effectiveness of home follow-up (Home F/U) to complete the final study evaluation on potentially “lost” participants by: 1) evaluating the impact of including and excluding potentially “lost” participants (e.g., those who required Home F/U to complete the final evaluation) on the rates of study complications; 2) examining the relationship between timing and number of complications on the requirement for subsequent Home F/U; and 3) determining predictors of those who required Home F/U.</p> <p>Methods</p> <p>We used data from a randomized controlled trial (RCT) conducted from 1991–1994 among coronary artery bypass graft surgery patients that investigated the effect of High mean arterial pressure (MAP) (intervention) vs. Low MAP (control) during cardiopulmonary bypass on 5 complications: cardiac morbidity/mortality, neurologic morbidity/mortality, all-cause mortality, neurocognitive dysfunction and functional decline. We enhanced completion of the final 6-month evaluation using Home F/U.</p> <p>Results</p> <p>Among 248 participants, 61 (25%) required Home F/U and the remaining 187 (75%) received Routine F/U. By employing Home F/U, we detected 11 additional complications at 6 months: 1 major neurologic complication, 6 cases of neurocognitive dysfunction and 4 cases of functional decline. Follow-up of 61 additional Home F/U participants enabled us to reach statistical significance on our main trial outcome. Specifically, the High MAP group had a significantly lower rate of the Combined Trial Outcome compared to the Low MAP group, 16.1% vs. 27.4% (p=0.032). In multivariate analysis, participants who were ≥ 75 years (OR=3.23, 95% CI 1.52-6.88, p=0.002) or on baseline diuretic therapy (OR=2.44, 95% CI 1.14-5.21, p=0.02) were more likely to require Home F/U. In addition, those in the Home F/U group were more likely to have sustained 2 or more complications (p=0.05).</p> <p>Conclusions</p> <p>Home visits are an effective approach to reduce attrition and improve accuracy of study outcome reporting. Trial results may be influenced by this method of reducing attrition. Older participants, those with greater medical burden and those who sustain multiple complications are at higher risk for attrition.</p>
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spelling doaj.art-c8a509e8bb6448c586dbf14f79aedec82022-12-22T03:26:38ZengBMCBMC Medical Research Methodology1471-22882012-11-0112117810.1186/1471-2288-12-178Attrition in longitudinal randomized controlled trials: home visits make a differencePeterson Janey CPirraglia Paul AWells Martin TCharlson Mary E<p>Abstract</p> <p>Background</p> <p>Participant attrition in longitudinal studies can introduce systematic bias, favoring participants who return for follow-up, and increase the likelihood that those with complications will be underestimated. Our aim was to examine the effectiveness of home follow-up (Home F/U) to complete the final study evaluation on potentially “lost” participants by: 1) evaluating the impact of including and excluding potentially “lost” participants (e.g., those who required Home F/U to complete the final evaluation) on the rates of study complications; 2) examining the relationship between timing and number of complications on the requirement for subsequent Home F/U; and 3) determining predictors of those who required Home F/U.</p> <p>Methods</p> <p>We used data from a randomized controlled trial (RCT) conducted from 1991–1994 among coronary artery bypass graft surgery patients that investigated the effect of High mean arterial pressure (MAP) (intervention) vs. Low MAP (control) during cardiopulmonary bypass on 5 complications: cardiac morbidity/mortality, neurologic morbidity/mortality, all-cause mortality, neurocognitive dysfunction and functional decline. We enhanced completion of the final 6-month evaluation using Home F/U.</p> <p>Results</p> <p>Among 248 participants, 61 (25%) required Home F/U and the remaining 187 (75%) received Routine F/U. By employing Home F/U, we detected 11 additional complications at 6 months: 1 major neurologic complication, 6 cases of neurocognitive dysfunction and 4 cases of functional decline. Follow-up of 61 additional Home F/U participants enabled us to reach statistical significance on our main trial outcome. Specifically, the High MAP group had a significantly lower rate of the Combined Trial Outcome compared to the Low MAP group, 16.1% vs. 27.4% (p=0.032). In multivariate analysis, participants who were ≥ 75 years (OR=3.23, 95% CI 1.52-6.88, p=0.002) or on baseline diuretic therapy (OR=2.44, 95% CI 1.14-5.21, p=0.02) were more likely to require Home F/U. In addition, those in the Home F/U group were more likely to have sustained 2 or more complications (p=0.05).</p> <p>Conclusions</p> <p>Home visits are an effective approach to reduce attrition and improve accuracy of study outcome reporting. Trial results may be influenced by this method of reducing attrition. Older participants, those with greater medical burden and those who sustain multiple complications are at higher risk for attrition.</p>http://www.biomedcentral.com/1471-2288/12/178Loss to follow-upCoronary artery bypass graft (CABG) surgeryCardiovascular diseaseEpidemiological methodsDropoutsNon-response biasNon respondentsHome visitPredictors of attritionStrategies to reduce attrition
spellingShingle Peterson Janey C
Pirraglia Paul A
Wells Martin T
Charlson Mary E
Attrition in longitudinal randomized controlled trials: home visits make a difference
BMC Medical Research Methodology
Loss to follow-up
Coronary artery bypass graft (CABG) surgery
Cardiovascular disease
Epidemiological methods
Dropouts
Non-response bias
Non respondents
Home visit
Predictors of attrition
Strategies to reduce attrition
title Attrition in longitudinal randomized controlled trials: home visits make a difference
title_full Attrition in longitudinal randomized controlled trials: home visits make a difference
title_fullStr Attrition in longitudinal randomized controlled trials: home visits make a difference
title_full_unstemmed Attrition in longitudinal randomized controlled trials: home visits make a difference
title_short Attrition in longitudinal randomized controlled trials: home visits make a difference
title_sort attrition in longitudinal randomized controlled trials home visits make a difference
topic Loss to follow-up
Coronary artery bypass graft (CABG) surgery
Cardiovascular disease
Epidemiological methods
Dropouts
Non-response bias
Non respondents
Home visit
Predictors of attrition
Strategies to reduce attrition
url http://www.biomedcentral.com/1471-2288/12/178
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AT charlsonmarye attritioninlongitudinalrandomizedcontrolledtrialshomevisitsmakeadifference