Long-term follow-up of high risk preterm infants has become increasingly important as the proportion of infants surviving has increased steadily over the past several decades. It is well known that these infants are at increased risk of cognitive impairment. (Class) With this increase in at risk survivors, many clinical research questions arise that can only be answered by long-term follow-up studies. (Vohr, Teune) Clinical trials that examine common perinatal therapies should also include a long term follow-up component in their research to examine later neurodevelopmental outcomes in their cohorts. Although there is no prescribed protocol dictating which specific ...view middle of the document...
During our review of the literature, we were not able to find any reports of error rates committed on Bayley assessments. The goal of the present study was to identify the types and numbers of errors detected by central source document verification (SDV) on the Bayley Scales of Infant and Toddler Development 3rd edition (Bayley-III) examinations completed during the 18 month follow-up phase of the Canadian Oxygen Trial (COT).
MATERIALS and METHODS
The COT study was an international multi-centered trial that enrolled 1201 infants with gestational ages of 23 weeks 0 days through 27 weeks 6 days during the first 24 hours after birth to receive a concentration of supplemental oxygen to target arterial oxygen saturations 85% to 89% or 91% to 95%. Follow-up assessments were performed at a corrected age of 18-21 months on all surviving children to determine the rate of death before 18 months or survival with severe neurodevelopmental disability. Details of the trial design and outcomes of the COT trial have been reported previously. (refSchmidt)
Review process during main COT trial
As part of the primary composite outcome at 18-21 months corrected age, the Bayley-III test was administered in COT to evaluate cognitive and language abilities. The Bayley-III is a standardized assessment used to measure the developmental functioning of infants and children from 1 to 42 months old. Experienced Bayley-III examiners administered the test in all study sites. Standard operating procedure at the data coordinating centre (DCC) is to perform central and comprehensive SDV for all psychometric tests that are components of the primary outcome measure. During COT follow-up, copies of the Bayley-III source documents were transmitted to the DCC and were centrally reviewed for accuracy and completeness. Bayley-III source documents consisted of a copy of the Record Form summary page as well as all test booklet pages containing the subtest items that were administered and scored. Discrepancies were identified, resolved and corrected through a documented data clarification process with input from Bayley examiners at the respective study sites. Queries that were unable to be resolved through this process were sent to an external committee for adjudication.
Re-review process during current trial
In the current study, one assessor (JD) re-reviewed and tabulated all errors identified in the original SDV process for 936 of 954 (98%) study participants for whom the outcome of cognitive or language delay was known. Assessments that were previously deemed as error-free during the main study review were not re-examined for errors in the current study. These cases were counted as containing no errors. Errors that were identified were classified into 5 main categories: age calculation, documenting/applying scoring rules, raw score addition, normative table look-ups, and data entry discrepancies using predetermined definitions. A 15% random sample was...