Cost of diabetes mellitus in Africa: a systematic review of existing literature

Table 3 Quality index score for studies included in review

Question	Reference index in Additional file 3
Question	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26
1. Was a clear definition of the illness given?	+	√	√	+	√	+	√	+	+	√	√	√	+	√	√	√	+	√	√	+	+	+	x	√	√	+
2. Were epidemiological sources carefully described?	+	n.a	√	√	+	n.a	√	√	√	√	√	√	√	√	√	√	√	√	+	√	√	√	x	√	√	x
3. Were costs sufficiently disaggregated?	√	√	√	+	+	+	+	+	x	√	+	√	√	√	√	+	+	√	√	+	+	√	√	+	√	+
4. Were activity data appropriately assessed?	√	√	+	√	√	+	√	√	√	√	√	√	√	+	√	√	√	+	√	√	√	√	√	√	√	√
5. Were the sources of all cost values analytically described	√	+	√	+	+	+	+	√	√	+	√	√	√	+	+	√	√	+	√	√	√	√	√	√	√	+
6. Were unit costs appropriately valued?	+	√	√	√	√	√	√	+	√	+	√	+	√	+	√	√	√	+	√	√	√	+	√	√	√	√
7. Were the methods adopted carefully explained?	√	√	√	√	+	+	+	√	√	√	+	+	√	+	+	√	√	+	+	+	√	√	√	√	√	+
8. Were costs discounted	n.a	n.s	+	n.a	n.a	n.a	n.a	n.a	n.a	n.a	n.a	n.a	+	n.a	n.a	n.a	n.a	n.a	n.a	n.a	n.a	n.a	+	n.a	n.a	n.a
9. Were the major assumptions tested in a sensitivity analysis?	x	x	√	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	x	√	x	x	x	√
10. Was the presentation of study results consistent with the methodology of the study?	√	√	√	√	√	+	√	√	+	√	√	√	√	√	√	√	√	√	√	√	√	√	√	√	√	√
Total score by study
√ Yes	5	6	8	5	4	1	5	5	5	6	6	6	7	4	6	7	6	4	6	5	6	7	6	7	8	4
+ partially	3	1	2	3	4	6	3	3	2	2	2	2	2	4	2	1	2	4	2	3	2	2	1	1	0	4
x No	1	1	0	1	1	1	1	1	2	1	1	1	1	1	1	1	1	1	1	1	1	0	3	1	1	1
n.a not applicable	1	1	0	1	1	2	1	1	1	1	1	1	0	1	1	1	1	1	1	1	1	1	0	1	1	1

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