Research output on systemic sclerosis and socio-economic factors: An analysis of country-level panel data

Abstract

Background Systemic sclerosis (SSc) is a rare detrimental disease warranting mobilization of global research efforts. We aimed to evaluate impacts of country factors on research output over SSc to identify solutions promoting research. Methods Publication production on SSc during 1969–2018 and data for structural and policy factors were collected from public sources. Effects of country-level factors were investigated through panel regression in WHO member countries. Difference-in-differences analysis assessed the impacts of rare disease legislation. Effect heterogeneity across income levels was evaluated using group regression. Results SSc publications showed increasing annual growth rate (−0.3% during 1969–1983 vs. 6.9% during 2000–2018). Totally, ten countries published 12 261 (77.5%) SSc publications but another 87 countries produced none. High-income countries with higher GDP, larger population, and higher health expenditure tended to publish more (p<0.001). Whereas in middle-income countries (MICs) SSc scientific output was significantly associated with expenditure on research and development( p <0.001). Rare disease legislation increased annual publication production by 62.8% (95% CI 0.390–0.867; p <0.001) averagely. Notably, the effect of legislation was swift and lasting in MICs during the first five years. No significant impact was found with GDP per capita, female percentage, and political indicators. Conclusions SSc research output increased over time with substantial country disparities. Effective health policies facilitating research should be expanded especially among MICs to accelerate global advancement.