Large scale evidence and replication: insights from rheumatology and beyond

Replication Research Series-Paper 1 : A concept analysis and meta-narrative review established a comprehensive theoretical definition of replication research to improve its use

OBJECTIVES

The aim of this study is to clarify the concept of replication research to improve its appropriate use by researchers, editors, research funders, and decision makers.

STUDY DESIGN AND SETTING

We combined concept analysis and metanarrative review methods to synthetize knowledge on replication research from various scientific fields. We used multiple search strategies to identify the relevant literature published before April 2018. We summarized the data by seeking commonalities and differences in underlying conceptual and theoretical assumptions in the literature.

RESULTS

A total of 153 articles from various disciplines were included. The analysis led to the identification of three major definitions of replication: the repetition of a previous study, the extension of a previous study, and the road-testing of a theory. Attributes, conditions required to conduct replication studies, concerns related to the interpretation of replication studies, and diverse replication research typologies were synthesized, combined, and analyzed. Based on this metanarrative review, a comprehensive theoretical definition of replication research was formulated.

CONCLUSION

This study can support the adoption of a shared understanding and recognition of the indispensable nature of replication research for the sound development of knowledge in all research fields.

Transdiagnostic Risk Calculator for the Automatic Detection of Individuals at Risk and the Prediction of Psychosis: Second Replication in an Independent National Health Service Trust

BACKGROUND

The benefits of indicated primary prevention among individuals at Clinical High Risk for Psychosis (CHR-P) are limited by the difficulty in detecting these individuals. To overcome this problem, a transdiagnostic, clinically based, individualized risk calculator has recently been developed and subjected to a first external validation in 2 different catchment areas of the South London and Maudsley (SLaM) NHS Trust.

METHODS

Second external validation of real world, real-time electronic clinical register-based cohort study. All individuals who received a first ICD-10 index diagnosis of nonorganic and nonpsychotic mental disorder within the Camden and Islington (C&I) NHS Trust between 2009 and 2016 were included. The model previously validated included age, gender, ethnicity, age by gender, and ICD-10 index diagnosis to predict the development of any ICD-10 nonorganic psychosis. The model's performance was measured using Harrell's C-index.

RESULTS

This study included a total of 13702 patients with an average age of 40 (range 16-99), 52% were female, and most were of white ethnicity (64%). There were no CHR-P or child/adolescent services in the C&I Trust. The C&I and SLaM Trust samples also differed significantly in terms of age, gender, ethnicity, and distribution of index diagnosis. Despite these significant differences, the original model retained an acceptable predictive performance (Harrell's C of 0.73), which is comparable to that of CHR-P tools currently recommended for clinical use.

CONCLUSIONS

This risk calculator may pragmatically support an improved transdiagnostic detection of at-risk individuals and psychosis prediction even in NHS Trusts in the United Kingdom where CHR-P services are not provided.

Pharmacogenetics of anti-TNF treatment in patients with rheumatoid arthritis

TNF-blocking strategies are widely used in the treatment of rheumatoid arthritis (RA). Three anti-TNF agents are registered for use in RA: etanercept, infliximab and adalimumab. Although anti-TNF therapy is very effective in controlling disease activity and slowing down radiological damage, prolonged response is only seen in approximately 70% of the patients. The causes for nonresponse in the remaining patients have not yet been elucidated. Pharmacogenetic studies focusing on genes involved in RA etiology (and/or progression) and in the pharmacokinetics of TNF-blocking agents have identified markers associated with anti-TNF treatment outcome. In the future, more exhaustive, less hypothesis-driven search strategies are expected to discover additional markers. Identification of these markers might be viewed as the first step towards tailored TNF-blocking therapy for patients with RA. Nevertheless, replication and large prospective studies will be needed to demonstrate the validity of the identified genetic markers before implementation into daily clinical practice.

Association between PADI4 and rheumatoid arthritis: a meta-analysis

OBJECTIVE

Polymorphisms and haplotypes of the peptidylarginine deiminase type 4 gene (PADI4) have been reported to be associated with rheumatoid arthritis (RA) in a Japanese population. However, subsequent replication studies showed conflicting results. The aim of this study was to determine whether meta-analysis would prove the existence of the association.

METHODS

PubMed was searched using the term 'PADI4' for articles from the publication of the first study to December 2005. Replication studies that tested the association between PADI4 and RA were reviewed for meta-analysis. The Breslow-Day test for homogeneity across the studies was calculated. The Mantel-Haenszel procedure was used to pool odds ratios (OR) with 95% confidence intervals (CI) to evaluate the association.

RESULTS

Six replication studies, one from Japan and five from Europe and North America, fulfilled the selection criteria for inclusion in the meta-analysis. Homogeneity was confirmed across the replication studies. The common OR was 1.14 (95% CI = 1.07-1.21) for allelic distribution. The association was confirmed when only five replication studies in the European descent populations were combined (P = 0.0096, common OR = 1.10).

CONCLUSIONS

Our meta-analysis showed a positive association between PADI4 and RA not only in the Japanese population but also in populations of European descent.