Table 2

Evidence profile and assessment of confidence in the review findings as per GRADE-CERQual methodology

	Review finding	Studies contributing to the finding	Methodological limitations	Coherence	Adequacy	Relevance	CERQual assessment of confidence in the evidence	Explanation of CERQual assessment
1	Strong public engagement (eg, networking and disseminating appealing, clear, and locally relevant information) facilitated crowdfunding for research.	2, 3, 5, 6, 7, 8, 9	Moderate methodological limitations due to limited reflexivity, lack of transparency on recruitment strategy, and unclear ethical considerations Two studies (5 and 6) lacked formal qualitative analysis	Minor concerns about coherence	Minor concerns regarding adequacy due to contributions from seven studies with moderately thick data.	Minor concerns about relevance, although six studies presented data from high income countries. Only one study (9) presents globally acquired data	Moderate confidence	Minor concerns over coherence, adequacy, and relevance. Moderate methodological limitations.
2	Crowdfunding expanded bidirectional communication between researchers and the public. It opened a channel between researchers and the public, and increased the public’s trust, awareness, and understanding of science.	5, 6, 7, 9	Serious methodological limitations (two studies with no or minor concerns (7,9) and two studies (5,6) with severe concerns following incomplete analysis on a very small sample)	Moderate concerns about coherence due to study findings based on insufficiently analysed data	Serious concerns about adequacy due to weak and at times incomplete analysis presented in 2 out of 4 studies contributing to this review finding.	Minor concerns about relevance, with three studies mainly focused on crowdfunding and research success, one study focused on selected platforms from high income countries alone	Low confidence	Due to minor concerns about relevance, Moderate concerns about coherence and Serious concerns about adequacy and Serious methodological limitations
3	Correlates of funding success included lower funding targets, researcher endorsements, the offer of rewards, testimonials, and input from known NGOs. Projects were also more successful if they were hosted on scientific crowdfunding platforms.	2, 7, 9	Minor methodological limitations, robust qualitative analysis presented from all three studies. Strong methodology presented with four conceptual frameworks in one study (9)	Moderate concerns about coherence, because one study finding (9) contradicts another (2)	Moderate concerns regarding adequacy The findings from two studies (2,9) are limited to one platform	Minor concerns about relevance All studies focused on success indicators for crowdfunding	Moderate confidence	Minor concerns for methodological limitations and relevance but moderate concerns for coherence and adequacy
4	Students, early career researchers, and people using innovative methods were more likely to meet their crowdfunding goals and benefit more from the process.	3, 4, 7, 9	Moderate methodological limitations due to lack of reflexivity (4, 7, 9); unclear recruitment strategy and limited data analysis (3)	Minor concerns about coherence	Moderate concerns about adequacy Due to three contributing studies with thick data (4, 7, 9) and one study with moderately thick data	Moderate concerns about relevance All studies are relevant, but three contributing studies are only focused on high-income contexts	Moderate confidence	Minor concerns regarding coherence. Moderate concerns regarding adequacy, relevance and methodological limitations.
5	Early-stage, proof-of -concept, pilot research and other smaller scale research projects were more suited to crowdfunding.	1, 2, 3, 4, 5, 6, 7	Moderate methodological limitations (two studies with no concerns (4,7) one study with minor concerns, 2 studies with moderate concerns due to small sample size and one study with severe concerns following incomplete analysis on a very small sample)	Minor concerns about coherence	Moderate concerns about adequacy due to low sample size from two studies (1,7) with moderately thick data from four studies (1,2,3,4) and thin data from one study	Minor concerns about relevance as all study mainly focus on crowdfunding for health research and related medical disease. Findings mainly are from high income settings with relevance in other settings.	Moderate confidence	Moderate level of confidence due to minor concerns about relevance and coherence and moderate concerns about adequacy and moderate methodological limitations
6	There are concerns regarding the ethics and risks of crowdfunding. Evidence suggests there was a lack of standardised peer review to ensure projects are ethically sound, valuable and of high scientific quality	2, 3, 6, 7, 9	Moderate methodological limitations Severe concerns for one study (6) due to a lack of formal qualitative analysis. Moderate or minor concerns for the other studies due to recruitment strategy ambiguity and limited reflexivity (2, 3, 7, 9)	Minor concerns about coherence	Moderate concerns about adequacy Due to three contributing studies with moderately thick data (2, 3, 7, 9) and one study with thin data (6)	Moderate concerns about relevance due to evidence from limited contexts, with data mainly from high-income settings.	Moderate confidence	Minor concerns regarding coherence. Moderate concerns regarding adequacy, relevance, and methodological limitations.
7	The risks associated with crowdfunding may be mitigated by involving expert reviewers to assess quality, developing partnerships with Non-Governmental Organisations (NGOs), universities and other institutions and by seeking mentorship from senior researchers	3, 4, 6, 7	Moderate methodological limitations due to limited reflexivity and a lack of formal data analysis in one study (6)	Moderate concerns about coherence due to gaps in the data that could specifically back this finding	Moderate concerns about adequacy three contributing studies with moderately thick data	Moderate concerns about relevance due to data coming only from high-income settings.	Low confidence	Moderate concerns regarding methodology, coherence, adequacy, and relevance.