A rapid research needs appraisal methodology to identify evidence gaps to inform clinical research priorities in response to outbreaks—results from the Lassa fever pilot

Table 2 Type of study designs identified for each clinical domain

Domain	Study design
Domain	Non-randomized controlled studies	Cohort studies	Case-control studies	Cross-sectional studies	Case series^#	Case report^#
Clinical phenotype and natural history of disease	1 article [18]	18 articles* [19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38]	3 articles [39,40,41]	7 articles [42,43,44,45,46,47,48]	21 articles [49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69]	27 articles [70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96]
Transmission and prevention		10 articles** [22, 29, 38, 97,98,99,100,101,102,103]		3 articles [42, 43, 104]	3 articles [61, 62, 105]	7 articles [73, 74, 83, 84, 91, 92, 106]
Diagnostics		5 articles** [19, 37, 107,108,109]	1 article [110]	2 articles [46, 111, 112]	1 article [69]	4 articles [55, 74, 82, 113]
Immune response		4 articles** [31, 32, 107, 114]		2 articles [44, 46]	6 articles [52, 65, 115,116,117,118]	9 articles [55, 70, 72, 73, 76, 86, 91,92,93]
Drug therapy and supportive care	1 article [119]	7 articles** [19, 21, 24, 38, 120,121,122]		3 articles [42, 123, 124]	8 articles [49, 51,52,53, 56, 64, 66, 125]	17 articles [55, 71, 73,74,75,76,77,78, 80, 81, 83, 85, 86, 89, 95, 96, 126]
Risk factors for more severe disease		3 articles [37, 38, 114]		1 article [44]

*4 not extracted
**1 not data extracted
^#Not extracted since higher level of evidence available for the domains covered in each article