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Published on: January 11, 2016
Recruitment bias in a population-based study of children with cerebral palsy
Jackie Parkes1, Claire Kerr, Brona C McDowell
1School of Nursing and Midwifery, Queen's University Belfast, Room 1.36, Mulhouse Building, Grosvenor Rd, Belfast, BT12 6BJ Ireland. j.parkes@qub.ac.uk
Insights
Recruitment bias in pediatric cerebral palsy studies was assessed. Clinic-based recruitment was more successful, but case registers are valuable for comprehensive sampling frames.
Area of Science:
- Pediatric Orthopedics
- Clinical Research Methodology
- Cerebral Palsy Studies
Background:
- Population-based studies are crucial for understanding childhood conditions.
- Cerebral palsy (CP) research requires effective recruitment strategies.
- Assessing recruitment bias is vital for study validity.
Purpose of the Study:
- To evaluate potential recruitment bias in a population-based study.
- To compare recruitment strategies for children with cerebral palsy.
- To assess the representativeness of participants in a locomotor ability study.
Main Methods:
- Utilized a population-based case register as a sampling frame.
- Employed a dual recruitment approach: orthopedic service and community pediatric network.
- Included children with cerebral palsy aged 4-16 years, able to walk ≥10m, in Northern Ireland.
Main Results:
- The orthopedic service identified distinct patient subgroups.
- Higher response and recruitment rates were achieved via the orthopedic service.
- Overall participation was 37.8%, with no evidence of systematic demographic or clinical bias.
- A single reminder increased recruitment by 10%.
Conclusions:
- Clinic-based recruitment may be more effective but requires careful consideration.
- Comprehensive case registers are valuable for providing baseline population data.
- Case registers enhance clinical research by offering robust sampling frames.
Objective:
The purpose of this analysis was to assess recruitment bias in a population-based study of locomotor ability in children with cerebral palsy.
Method:
A population-based case register was used as a sampling frame and was considered a highly ascertained record of children with the condition. A twin track approach to recruitment for the Locomotor Study was adopted through: (1) a specialist orthopedic service and (2) a community pediatric network on behalf of the case register. The subjects included children with cerebral palsy aged 4 to 16 years in 2003, able to walk > or = 10 m, and a resident in Northern Ireland, as well as their parents.
Results:
The Orthopaedic Service identified clinically distinct children with cerebral palsy in terms of type, severity, age, and geographic residence. More families responded to an invitation, and more were ultimately recruited into the study via the Orthopaedic Service compared with a case register using community pediatric contacts. Overall, 37.8% of the eligible cerebral palsy population participated in the Locomotor Study, but there was no evidence of any systematic biases in demographic or key clinical characteristics when compared with nonparticipants. One follow-up reminder led to an increase in recruitment of 10%.
Conclusions:
Care must be taken in the recruitment of children with cerebral palsy through clinic-based populations, although these routes may prove more successful in follow-up. Provided they are comprehensive, case registers have a valuable contribution to make to clinical research by providing a sampling frame including information on baseline characteristics of an affected population.
