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Published on: January 11, 2016
[Loss to follow-up and cerebral palsy]
M López Maestro1, C R Pallás Alonso, J de La Cruz Bértolo
1Servicio de Neonatología, Hospital 12 de Octubre, Madrid, España.
Insights
Children lost to follow-up, particularly those from socially disadvantaged backgrounds, have a significantly higher risk of developing disabling cerebral palsy. This highlights potential biases in health program assessments and study results.
Area of Science:
- Neonatal care and developmental pediatrics.
- Public health and epidemiology.
- Clinical trial methodology and bias analysis.
Background:
- Longer follow-up programs are associated with increased patient attrition.
- Loss to follow-up can compromise healthcare goal achievement and study validity.
- Understanding factors influencing attrition is crucial for accurate health outcome assessment.
Purpose of the Study:
- To compare neonatal characteristics between followed-up and lost-to-follow-up children.
- To actively trace and evaluate children lost from the follow-up program.
- To determine the incidence of cerebral palsy in both followed-up and lost-to-follow-up cohorts.
Main Methods:
- A cohort of 601 neonates (birth weight <1,500g) was established between 1991-1997.
- 447 infants were enrolled in a follow-up program, with cerebral palsy assessed at 2 years.
- A targeted search and telephone questionnaire were used to trace and update data for lost children.
Main Results:
- Twenty percent of infants were lost to follow-up by age 2; 57% of these were contacted via telephone.
- No significant neonatal characteristic differences existed, except for critical social disadvantage (10% vs. 41%).
- Disabling cerebral palsy occurred in 7% of followed-up children versus 23% of lost-and-traced children (RR 3.1).
Conclusions:
- Children lost to follow-up exhibit a threefold increased risk of disabling cerebral palsy.
- Failure to account for lost participants can lead to underestimation of disability rates.
- This bias impacts the evaluation of healthcare interventions and research findings.
Background:
The longer follow-up programs last, the greater the loss to follow-up. These losses to follow-up may undermine the completion of health care goals and the validity of study results.
Objectives:
1) To compare neonatal characteristics in children easily followed-up and in those lost to follow-up. 2) To trace and assess children lost to follow-up. 3) To estimate the occurrence of cerebral palsy in children easily followed-up and in those lost to follow-up.
Methods:
From 1991 to 1997, 601 neonates with a birth weight under 1,500 g were admitted to the Neonatology Department. At discharge, 447 infants were included in the follow-up program. Moderate-to-severe cerebral palsy was assessed when the children were aged 2 years. A specific search strategy was implemented to find those children lost to follow-up. Data on the development of those traced were updated through a standardized telephone questionnaire.
Results:
Twenty percent of the children were lost to follow-up before the age of 2 years. Fifty-seven percent of those not available at this age were assessed by telephone interview. No differences were found in the neonatal characteristics of infants easily followed-up and those lost to follow-up except in situations of critical social disadvantage: 10 % in followed-up infants, 41 % in infants lost to follow-up. Disabling cerebral palsy was observed in 7 % of children easily followed-up and in 23 % of those lost and traced (relative risk: 3.1, 1.5-5.5).
Conclusions:
The risk of having disabling cerebral palsy is three times higher in children lost to follow-up than in those easily followed-up. Dismissing this source of bias may underestimate disability rates when assessing health care programs or when interpreting study results.
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