| Title: |
Impacts of study design on sample size, participation bias, and outcome measurement: A case study from bicycling research |
| Authors: |
Branion-Calles, M; Winters, M; Nelson, T; De Nazelle, A; Int Panis, L; Avila-Palencia, I; Anaya-Boig, E; Rojas-Rueda, D; Dons, E; Gotschi, T |
| Contributors: |
Commission of the European Communities |
| Source: |
12 ; 1 |
| Publisher Information: |
Elsevier |
| Publication Year: |
2019 |
| Collection: |
Imperial College London: Spiral |
| Subject Terms: |
Science & Technology; Life Sciences & Biomedicine; Technology; Public; Environmental & Occupational Health; Transportation; Bicycling; Bias; Exposure; Survey participation; Longitudinal; Cross-sectional; Study design; PROSPECTIVE COHORT; FOLLOW-UP; CYCLISTS; 1117 Public Health and Health Services; 1205 Urban and Regional Planning; 1507 Transportation and Freight Services |
| Description: |
Introduction Measuring bicycling behaviour is critical to bicycling research. A common study design question is whether to measure bicycling behaviour once (cross-sectional) or multiple times (longitudinal). The Physical Activity through Sustainable Transport Approaches (PASTA) project is a longitudinal cohort study of over 10,000 participants from seven European cities over two years. We used PASTA data as a case study to investigate how measuring once or multiple times impacted three factors: a) sample size b) participation bias and c) accuracy of bicycling behaviour estimates. Methods We compared two scenarios: i) as if only the baseline data were collected (cross-sectional approach) and ii) as if the baseline plus repeat follow-ups were collected (longitudinal approach). We compared each approach in terms of differences in sample size, distribution of sociodemographic characteristics, and bicycling behaviour. In the cross-sectional approach, we measured participants long-term bicycling behaviour by asking for recall of typical weekly habits, while in the longitudinal approach we measured by taking the average of bicycling reported for each 7-day period. Results Relative to longitudinal, the cross-sectional approach provided a larger sample size and slightly better representation of certain sociodemographic groups, with worse estimates of long-term bicycling behaviour. The longitudinal approach suffered from participation bias, especially the drop-out of more frequent bicyclists. The cross-sectional approach under-estimated the proportion of the population that bicycled, as it captured ‘typical’ behaviour rather than 7-day recall. The magnitude and directionality of the difference between typical weekly (cross-sectional approach) and the average 7-day recall (longitudinal approach) varied depending on how much bicycling was initially reported. Conclusions In our case study we found that measuring bicycling once, resulted in a larger sample with better representation of sociodemographic groups, but different ... |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
Journal of Transport and Health; http://hdl.handle.net/10044/1/80109; 602624 |
| DOI: |
10.1016/j.jth.2019.100651 |
| Availability: |
http://hdl.handle.net/10044/1/80109; https://doi.org/10.1016/j.jth.2019.100651 |
| Rights: |
© 2019 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/ |
| Accession Number: |
edsbas.51FEDF24 |
| Database: |
BASE |