. 2021 Sep 23;22:251. doi: 10.1186/s12931-021-01841-6

Table 1.

Characteristics of included observational and qualitative studies

Income group*	Country	Study population	Study design	Sample size and study
				Newcastle–Ottawa scale score^†
				HQ	MQ	LQ
Patient delay
LIC	Ethiopia	People with TB	Cross-sectional	216[24], 296[25], 360[26], 382[27], 398[28], 425[29], 605[30], 706[31], 924[32]	129[33], 201[34], 226[35]
		People with presumptive TB	Case–control	838[36]
		People with presumptive TB	Cross-sectional	476[37], 843[38], 1006[39]	663[40], 763[41]
	Mozambique	People with TB	Cross-sectional		622[42]
	Tanzania	People with TB	Cross-sectional	639[43]	206[44]
	Tanzania	People with presumptive TB	Cross-sectional	3388[45]
LMIC	Angola	People with TB	Cross-sectional	385[46]
	Bangladesh	People with TB	Cross-sectional		7280[47]
	Cambodia	People with TB	Mixed-methods		96[48]
	India	People with TB	Cross-sectional	216[49], 234[50]	150[51], 261[52]
		People with TB (children)	Cross-sectional		175[53]
		People with presumptive TB	Cross-sectional	437[54]
	Indonesia	People with presumptive TB	Cross-sectional	194[55]	746[56]
	Kenya	People with TB	Cross-sectional			230[57]
	Kenya	People with presumptive TB	Cross-sectional		426[58]
	Nigeria	People with TB	Cross-sectional	160[59], 450[60]	102[61]
	Zambia	People with presumptive TB	Cross-sectional	6708[62]
	Zimbabwe	People with TB	Cross-sectional	383[63]
UMIC	Brazil	People with TB	Cross-sectional	139[64], 153[65]	97[66], 101[67], 199[68], 218[69], 304[70]
	Brazil	TB-HIV co-infection	Prospective cohort	201[71]
	China	People with TB	Cross-sectional	314[72], 1126[73], 2280[74]	146[75], 259[76], 314[77], 323[78], 819[79], 1083[80]
			Prospective cohort		202[81]
			Retrospective cohort	4677[82], 10356[20]	75401[21]
		People with presumptive TB	Cross-sectional		1005[83]
	Russia	People with TB	Cross-sectional	105[84]
	South Africa	General population	Cross-sectional		1020[85]
		People with presumptive TB	Cross-sectional		104[86]
		TB-HIV co-infection	Prospective cohort	891[87]
	Thailand	People with TB	Cross-sectional	443[88]	199[89]
Health system delay
LIC	Ethiopia	People with TB	Cross-sectional		201[34]
LIC	Nigeria	People with TB	Cross-sectional	470[90]
LMIC	Angola	People with TB	Cross-sectional	385[46]
UMIC	Brazil	People with TB	Cross-sectional		218[69], 304[70], 305[91]
	China	People with TB	Cross-sectional	314[72]	146[75]
			Prospective cohort		202[81]
			Retrospective cohort	4677[82]
	South Africa	TB-HIV co-infection	Cross-sectional	480[92]
Treatment delay
LIC	Tanzania	People with TB	Cross-sectional	1161[93]
LMIC	Bangladesh	People with TB	Cross-sectional		123[94]
	Cambodia	People with TB	Mixed-methods		96[48]
	India	People with TB	Cross-sectional	234[50], 344[95]	150[51]
			Mixed-methods	2027[96]
			Retrospective cohort	662[97], 1800[98]
	Zimbabwe	People with TB	Retrospective cohort	2443[99]
UMIC	China	People with TB	Cross-sectional	314[100]
	China	People with TB	Retrospective cohort	4677[82]
	South Africa	People with TB	Cross-sectional	210[101]
Total delay
LIC	Ethiopia	People with TB	Cross-sectional	216[24], 296[25], 328[102], 382[27]	201[34]
	Mozambique	People with TB	Cross-sectional		622[42]
	Tanzania	People with TB	Cross-sectional		206[44]
LMIC	Bangladesh	People with TB	Cross-sectional		7280[47]
	India	People with TB	Cross-sectional	216[49], 289[103]
	India	People with TB	Retrospective cohort	656[104]
	Indonesia	People with TB	Cross-sectional		1116[105]
	Nigeria	People with TB	Cross-sectional	450[60]
	Pakistan	People with TB	Cross-sectional	844[106]	252[107], 269[108]
UMIC	Brazil	People with TB	Case–control	242[109]
	Brazil	People with TB	Cross-sectional		304[70]
	South Africa	People with TB	Cross-sectional	210[101]
	South Africa	TB-HIV co-infection	Prospective cohort	891[87]
	Thailand	People with TB	Cross-sectional	443[88]

Income group*	Country	Study population	Methods of analysis	Study and sample size	ConQual rating^‡	CASP score^§
Qualitative studies
LIC	Ethiopia	People with TB, contacts of people with TB, and health care workers	Phenomenological analysis	5 IDIs and 2 FGDs [110]	HQ	HQ
		People with TB	Thematic analysis	26 IDIs [111]	HQ	HQ
		People with TB and policymakers	Thematic analysis	19 IDIs [112]	HQ	HQ
	Mozambique	Caretakers of people with TB	Content analysis	35 IDIs [113]	HQ	HQ
	Tanzania	People with TB and traditional healers	Content analysis	32 IDIs [114]	HQ	HQ
LMIC	Bangladesh	People with TB	Qualitative analysis of open-ended survey questions	229 interviews [115]	MQ	MQ
	Bangladesh	People with TB and health care workers	Qualitative analysis using apriori codes	24 IDIs [116]	HQ	HQ
	Cambodia	People with TB, health care workers, and community volunteers	Thematic analysis	43 IDIs and 6 FGDs [48]	MQ	HQ
	Cambodia	People with TB and the general population	Thematic analysis	13 FGDs [117]	HQ	HQ
	India	Health care workers	Thematic analysis	16 IDIs [118]	HQ	HQ
		People with TB	Not presented in the article	76 IDIs [119], 75 structured interviews [96]	MQ	MQ
			Not presented in the article	108 structured interviews [120]	MQ	HQ
			Qualitative analysis of open-ended survey questions	229 interviews [115]	MQ	MQ
		People with TB and health care workers	Qualitative analysis using apriori codes	19 IDIs [121]	MQ	HQ
		People with TB and health care workers	Thematic analysis	71 IDIs [122]	HQ	HQ
	Indonesia	People with TB and community volunteers	Thematic analysis	67 IDIs and 6 FGDs [123]	HQ	HQ
	Indonesia	People with TB, TB survivors, village leaders, and community volunteers	Not presented in the article	50 IDIs and 3 FGDs [124]	HQ	HQ
	Nigeria	General population	Thematic analysis	56 IDIs [125]	MQ	HQ
	Philippines	People with TB and the general population	Thematic analysis	22 IDIs and 3 FGDs [126]	HQ	HQ
	Zambia	People with TB and community volunteers	Thematic analysis	30 IDIs and 6 FGDs [127]	MQ	HQ
	Zimbabwe	People with presumptive TB	Grounded theory	20 IDIs [128]	HQ	HQ
UMIC	Brazil	Health care workers	Discourse analysis	16 IDIs [129]	MQ	HQ
		People with TB	Content analysis	23 IDIs [130]	MQ	HQ
			Thematic analysis	7 IDIs [131]	MQ	HQ
			Discourse analysis	7 IDIs [132]	HQ	MQ
	China	People with TB	Qualitative analysis of open-ended survey questions	70 interviews [133]	MQ	MQ
		People with TB (migrants)	Thematic analysis	34 IDIs [134]	MQ	HQ
		People with TB (migrants), People with presumptive TB, and health care workers	Framework approach	60 IDIs and 12 FGDs [135]	MQ	HQ
		People with TB, health care workers, policymakers, and community volunteers	Thematic analysis	47 IDIs and 5 FGDs [136]	MQ	HQ
	Russia	People with TB	Grounded theory	5 FGDs [137]	HQ	HQ
	Russia	People with TB and health care workers	Grounded theory	32 IDIs and 11 participants in FGDs (number of FGDs not specified) [138]	HQ	HQ
	South Africa	Contacts of people with TB, health care workers, policymakers, and people with TB (miners)	Thematic analysis and grounded theory	104 applied ethnography using formal/informal IDIs, FGDs, field notes, and participant observations [139]	HQ	HQ
		Health care workers, village leaders, and researchers	Thematic analysis	12 IDIs [140]	HQ	HQ
		People with TB		41 IDIs [141]	MQ	HQ
		People with TB, contacts of people with TB, and health care workers		25 IDIs and 4 FGDs [142]	HQ	HQ
		People with TB, the general population, and community volunteers		93 reports from participatory research and participants observation [143]	HQ	HQ
		People with TB and general population	Thematic analysis and grounded theory	8 IDIs [144]	HQ	HQ
	Thailand	People with TB (migrants) and health care workers	Thematic analysis	12 IDIs and 11 FGDs [145]	MQ	HQ

Each number at the normal line of type in each cell referred to the sample size of each discrete study that shared the respective characteristics (country, study population, study design, and study quality). The number/s in bracket indicate the source article/s. Blank cells indicated that no studies of a particular set of characteristics were identified and included in this review

CASP critical appraisal skills program; FGD focus group discussions; HQ high quality, IDI in-depth interviews; LIC low-income countries, LMIC lower-middle-income countries, LQ low quality; MQ moderate quality, TB tuberculosis, UMIC upper-middle-income countries,

*Based on World Bank classification. Low-income economies—gross national income (GNI) per capita $1,025 or less in 2018; lower-middle-income economies—GNI per capita between $1,026 and $3,995; upper-middle-income economies—GNI per capita between $3,996 and $12,375

^†Study quality was assessed using the Newcastle–Ottawa scale. The highest possible score for cross-sectional studies was 10 (5 for selection, 2 for comparability, and 3 for outcome). The highest possible score for case–control studies was 9 (4 for selection, 2 for comparability, and 3 for exposure). The highest possible score for cohort studies was 9 (4 for selection, 2 for comparability, and 3 for exposure). Studies that scored 0–3 were regarded as LQ, 4–6 were regarded as MQ, and ≥ 7 were regarded as HQ

^‡All papers were pre-ranked (high, moderate, low), and the levels were adjusted according to the dependability and credibility of the findings. We pre-ranked all papers as high. The ranking remained high if the papers were regarded as dependable, and the findings were unequivocal. We downgraded the paper from high to moderate if the papers scored 3 or less in terms of dependability or scored a mix of unequivocal and credible in terms of credibility

^§CASP for qualitative study had 10 questions to appraise the paper critically. We gave a score of 1 if the paper fulfilled a criterion, 0.5 if we could not tell if the paper fulfilled a criterion, and 0 if it did not fulfil a criterion. A score of 0–5 equated to LQ study, a score of 6–7 equated to MQ study, and a score of ≥ 8 equated to HQ study