The use of systematic review methods has been linked to a reduced probability of screening recommendations for rare diseases in newborns, as many do not assess evidence based on resultant benefits and harms, according to results of a study published in BMJ.
Sian Taylor-Phillips, PhD, of the Warwick Medical School, The University of Warwick, in Coventry, United Kingdom, and colleagues analyzed policy-making decisions concerning selection of conditions to screen for using the newborn blood spot test as well as journal articles, papers, legal documents, presentations, conference abstracts, and reports to determine whether systematic reviews were used to support screening recommendations.
Although effective early screening can save lives, unnecessary or ineffective screening can do harm through false positives and the accompanying psychological harm, as well as through increased costs to the healthcare system. The authors considered the extent to which test accuracy, the benefit of early detection, and the degree of overdiagnosis influenced the decision-making process.
The authors included 93 reports covering 104 conditions across 14 countries, with 276 recommendations. Systematic review formed the basis for only 22% of the recommendations. Interestingly, the odds of a recommendation favoring screening were decreased if the decision makers included a systematic review of the evidence as part of the process (odds ratio: 0.17). Decision makers did not evaluate evidence on test accuracy in 42% of recommendations. Likewise, they did not evaluate evidence on the benefits of early diagnosis in 30% of recommendations or the potential harm of overdiagnosis in 76%.
The authors noted that in each review, the more rigorous the assessment of the test accuracy, the less likely it was that screening would be recommended. The study indicated that in many cases, national policy decisions regarding the use of the newborn blood spot test are made without careful review of the evidence to support such decisions. Such reviews should be done initially, as once policy recommendations for screening of newborn diseases are issued, it is very difficult to reverse them.
The authors recommend that a systematic review of the literature should be done wherever possible as part of the decision-making process on screening programs. As full systematic review of the key elements of a screening program can be costly, the authors propose greater international collaboration to undertake such reviews. Furthermore, they argue that although health systems and other factors may vary from one country to another, the evidence about test accuracy, benefits of early detection, and harms associated with overdiagnosis should differ little from one country to the next.
Taylor-Phillips S, Stinton C, Ferrante di Ruffano L, Seedat F, Clarke A, Deeks JJ. Association between use of systematic reviews and national policy recommendations on screening newborn babies for rare diseases: systematic review and meta-analysis. BMJ. 2018;361:k1612.