Researchers at the University of Warwick, UK, have warned that many national recommendations on whether newborn screening should be considered for rare conditions do not assess evidence on the key benefits and harms.
An effective newborn screening programme can save lives, while those deemed ineffective can do more harm than good; however, decisions about which conditions to screen vary widely between countries, despite similar populations and healthcare systems.
The reasons for these differences are unclear, but there have been suggestions that differences in the evidence review process used to generate policy, in particular the use of systematic reviews, may play a role.
Assessing the systematic review
Systematic reviews bring together evidence from existing studies and then use statistical methods to summarise the results, which will help make evidence-based decisions.
A team of researchers led by Dr Sian Taylor-Phillips, associate professor at Warwick Medical School, assessed the systematic review method and how it affects national decisions on whether to screen for a range of conditions using the newborn blood spot test, which is offered to every baby to detect rare but serious health conditions.
The team’s analysis included 93 reports that assessed 104 conditions across 14 countries, giving a total of 276 recommendations.
How was screening favoured?
It was found that screening was favoured in 58% of the recommendations, not favoured in 36%, and not recommended either way in 7%.
Only 22% of the recommendations were based on evidence from a systematic review. Use of a systematic review was associated with a reduced probability of screening being recommended (38% versus 63%).
Evidence for test accuracy was not considered in 42% of recommendations, while evidence around the benefits of early detection and the potential harm of overdiagnosis was not considered in 30% and 76% of recommendations, respectively.
Evidence-based policy decisions
Taylor-Phillips said: “This study showed that many national policy decisions about whether to screen for conditions are being made without systematically reviewing the evidence.
“Yet it remains essential to make evidence-based policy decisions because once screening programmes are started they are difficult to stop.”
She has called for further research “to understand why policymakers do not employ systematic review methods in their evaluations of evidence.”
Press Release: University of Warwick