Table 2.

Thematic and sub thematic presentation of barriers for conducting clinical trials

No	Barriers for conducting clinical trial
	Thematic barriers	Sub-themes	References
1	Lack of financial and human capacity	Lack of funding	[40–51]
		Lack of skilled personnel	[40, 42, 44, 45, 48–50, 52, 53]
		Lack of awareness and motivation	[43, 45, 48, 49, 52, 53]
2	Ethical and regulatory system obstacles	Delay of approval decisions	[40, 42, 45, 46, 48, 49, 52, 53]
		Unskilled authorities	[42, 45, 48, 49]
		Complex and strict ethical and regulatory system	[48, 49, 51].
4	Lack of research environment	Lack of infrastructure	[45, 47–50]
		Lack of research materials/facilities	[40, 46, 47]
		Lack of conducive scientific atmosphere	[43, 45, 50]
5	Operational barriers	Unsupportive administrative system	[43, 45, 47, 48, 51, 52]
		Lack of/difficult patient recruitment	[40, 44, 47]
6	Competing demands	Lack of time	[40, 48, 51, 53]
		Other competing priorities	[40, 43, 45, 46, 48, 51, 53]