Table 2.
Review Characteristics
| n = 137 | % | |
|---|---|---|
| Language of the publication | ||
| English | 136 | 99.3% |
| German | 1 | 0.7% |
| Year of publication | ||
| 2005‐2009 | 11 | |
| 2005 | 2 | 1.5% |
| 2006 | 3 | 2.2% |
| 2007 | 2 | 1.5% |
| 2008 | 3 | 2.2% |
| 2009 | 1 | 0.7% |
| 2010‐2014 | 42 | |
| 2010 | 9 | 6.6% |
| 2011 | 4 | 2.9% |
| 2012 | 8 | 5.8% |
| 2013 | 10 | 7.3% |
| 2014 | 11 | 8.0% |
| 2015‐2019 | 65 | |
| 2015 | 10 | 7.3% |
| 2016 | 11 | 8.0% |
| 2017 | 5 | 3.6% |
| 2018 | 17 | 12.4% |
| 2019 | 22 | 16.1% |
| 2020‐2021 a | 19 | |
| 2020 a | 14 | 10.2% |
| 2021 a | 5 | 3.6% |
| Review type b | ||
| Group of systematic reviews | 58 | |
| Systematic review | 54 | 39.4% |
| Systematic review + meta‐analysis | 2 | 1.5% |
| Qualitative systematic review | 1 | 0.7% |
| Hermeneutic systematic review + case study | 1 | 0.7% |
| Group of nonsystematic reviews | 79 | |
| Literature review | 29 | 21.2% |
| Scoping review | 9 | 6.6% |
| Rapid review | 6 | 4.4% |
| Narrative review | 5 | 3.6% |
| Comprehensive review | 4 | 2.9% |
| Integrative review | 2 | 1.5% |
| Qualitative review | 2 | 1.5% |
| Realist review | 2 | 1.5% |
| Structured review | 2 | 1.5% |
| Critical interpretive synthesis | 1 | 0.7% |
| Critical review | 1 | 0.7% |
| Qualitative interpretive review | 1 | 0.7% |
| Synthetic review | 1 | 0.7% |
| Review + interviews or Delphi | 14 | 10.2% |
| Sources of funding of the review c | ||
| Governmental/intergovernmental organizations | 31 | 22.6% |
| Governmental research councils | 28 | 20.4% |
| Charitable trusts | 21 | 15.3% |
| Commercial organizations | 1 | 0.7% |
| Mixed sources | 12 | 8.8% |
| No source of funding reported | 44 | 32.1% |
| Country of the corresponding author | ||
| HICs d | 114 | 83.2% |
| United States | 43 | 31.4% |
| United Kingdom | 25 | 18.2% |
| Canada | 14 | 10.2% |
| Australia | 13 | 9.5% |
| The Netherlands | 6 | 4.4% |
| Belgium | 3 | 2.2% |
| Switzerland | 3 | 2.2% |
| Denmark | 1 | 0.7% |
| Germany | 1 | 0.7% |
| Ireland | 1 | 0.7% |
| Italy | 1 | 0.7% |
| Scotland | 1 | 0.7% |
| Sweden | 1 | 0.7% |
| Switzerland and United States | 1 | 0.7% |
| LMICs d | 22 | 16.1% |
| South Africa | 9 | 6.6% |
| India | 4 | 2.9% |
| Bangladesh | 1 | 0.7% |
| Brazil | 1 | 0.7% |
| Congo | 1 | 0.7% |
| Kenya | 1 | 0.7% |
| Nigeria | 1 | 0.7% |
| Pakistan | 1 | 0.7% |
| Senegal | 1 | 0.7% |
| Tanzania | 1 | 0.7% |
| Zambia | 1 | 0.7% |
| LMIC + HIC collaborations d | 1 | 0.7% |
| China and Australia | 1 | 0.7% |
| Income levels of targeted countries d | ||
| LMIC | 59 | 43.1% |
| HIC | 11 | 8.0% |
| LMIC + HIC | 2 | 1.5% |
| Not specified | 65 | 47.4% |
| The authors stated the elements of PICO e | ||
| Yes | 16 | 11.7% |
| No | 121 | 88.3% |
| Diseases, conditions, or care types of interest | ||
| Health care | ||
| Maternal–child health | 28 | 20.4% |
| HIV/AIDS | 25 | 18.2% |
| Other infectious diseases | 11 | 8.0% |
| Mental health | 4 | 2.9% |
| Cancer | 2 | 1.5% |
| Chronic diseases | 2 | 1.5% |
| Eye care | 1 | 0.7% |
| Palliative care | 1 | 0.7% |
| Social care and prevention | ||
| Physical activity | 4 | 2.9% |
| Sexual education | 4 | 2.9% |
| Violence | 2 | 1.5% |
| Nutrition | 6 | 4.4% |
| Reviews not focused on a particular disease | ||
| Health innovation regardless of disease | 29 | 21.2% |
| Improvement the health system | 18 | 13.1% |
| Search strategy used scaling‐related terms f | ||
| Yes | 50 | 36.5% |
| No | 64 | 46.7% |
| Not reported | 23 | 16.8% |
| Timeframe for the search g | ||
| Yes | 105 | 76.6% |
| Not reported | 32 | 23.4% |
| Number of databases searched h | ||
| >1 | 94 | 68.6% |
| One database | 28 | 20.4% |
| Not specified | 5 | 3.6% |
| Not reported | 10 | 7.3% |
| Gray literature | ||
| Yes | 103 | 75.2% |
| Not reported | 34 | 24.8% |
| Quality of the studies was appraised | ||
| Yes | 40 | 29.2% |
| Not reported | 97 | 70.8% |
Abbreviations: HICs, high‐income countries; LMICs, low‐ and middle‐income countries; PICO, Participants, Intervention, Comparator, Outcome; WHO, World Health Organization.
Year incomplete, searched in databases August 6, 2020 and in gray literature July 20, 2021.
“Review type”: as described by the authors of their review; we did not verify whether the reviews met usual review characteristics of each review typology. “Literature review”: any review, review of published and gray literature, or evidence review.
“Governmental/intergovernmental organization”: government (e.g., Dutch government, health ministry), government or international development agencies, European organizations, USAID, WHO, World Bank, Global Fund. “Governmental research councils”: university grants, student grants, national research councils, Canadian Institutes of Health Research, National Institutes of Health, National Institute for Health and Care Research, National Health and Medical Research Council. “Charitable trust”: charitable foundations such as Grand Challenges Canada and Save the Children. “Mixed sources”: studies with more than one source of funding. “No source of funding”: studies did not report on funding sources or clearly indicated no grants or funding were received for the review.
Income country groups: based on the Organisation for Economic Co‐operation and Development Development Assistance Committee official list for development assistance56 and on authors’ reporting of the countries they included or would target.
PICO models: We also included PICo: Population, phenomena of Interest, and Context.
Authors stated, either in the Methods or in an appendix, that they had used the following search terms, with or without the addition of “up,” “out,” or “down”: scale, scaling, spread, rollout, diffusion, large‐scale, system‐wide dissemination, and scalability. “Not reported”: authors did not report search strategy or none of these terms were used.
“Not reported”: author did not state the date range of their search.
The authors stated the search strategies used which databases or journal; “Not specified”: authors stated they would search peer‐reviewed journals or databases without mentioning their names; “Not reported”: used when any information about the databases or journal searched was found in the review.