Predictors of Time to Sputum Culture Conversion Among Drug-Resistant Tuberculosis Patients in Oromia Region Hospitals, Ethiopia

Figures & data

Table 1 Socio-Demographic Characteristics of Drug-Resistant Tuberculosis Patients Following Treatment in Oromia Regional State Hospitals from 2012 to 2017, Oromia, Ethiopia

Characteristics	Number (%)	Time to Sputum Culture Conversion (Days)		Time to Sputum Smear Conversion (Days)
		Median	Inter-Quartile Range	Median	Inter-Quartile Range
Age category
≤18 years	27 (11.8)	31	26–81	30	19–34
19–24 years	39 (17.1)	61	34–107	31	29–60
25–30 years	88 (38.6)	61	47–88	34	29–54
31–40 years	50 (21.9)	86	46–89	38	31–58
≥41 years	24 (10.5)	61	26–81	35	27–61
Sex
Male	154 (60.2)	65	34–107	32	28–54
Female	10 (39.8)	58	34–87	34	29–55
Residence
Urban	160 (62.5)	60	32–90	34	29–55
Rural	96 (37.5)	64	49–98	31	28–54
Hospitals
Metu	12 (4.7)	–	–	31	30–31
Shanan Gibe	33 (12.9)	87	58–98	37	28–46
Nekemt	83 (32.4)	63	48–116	31	28–58
Bishoftu	8 (3.1)	51	30–70	31	30–39
Shashamane	39 (15.2)	90	56–120	31	29–53
Adama	60 (23.4)	46	30–63	35	29–62
Chiro	12 (4.7)	80	–	34	27–50
Dadar	9 (3.5)	26	16–35	29	21–43
Year of registration
2012	26 (11.4)	114	–	43	30–58
2013	62 (27.2)	87	59–111	31	28–55
2014	83 (36.4)	56	30–68	34	29–53
2015	52 (22.8)	44	29–81	35	29–50
2016	4 (1.8)	30	26–30	26	31–52
2017	3 (0.4)	65	–	–	–

Table 2 Clinical Characteristics of Drug-Resistant Tuberculosis Patients Following Treatment in Oromia Regional State Hospitals from 2012 to 2017, Oromia, Ethiopia

Characteristics	Number (%)	Time to Sputum Culture Conversion (Days)		Time to Sputum Smear Conversion (Days)
		Median	Inter-Quartile Range (Q1-Q3)	Median	Inter-Quartile Range (Q1-Q3)
Registration group
New	23(10.1)	58	34–70	42	29–54
Relapse	36(15.8)	65	-	31	30–39
Treatment after loss to follow up	7 (3.1)	89	45–93	45	28–89
Failure of treatment with a new first-line anti-TB regimen	46 (20.2)	51	36–80	35	29–47
Failure of retreatment with a first-line anti-TB regimen	110 (48.2)	63	31–107	32	27–56
Transfer in from another treatment center	5 (2.2)	53	53–90	31	31–53
Previous treatment with an unknown outcome	1 (0.4)	92	-	92	-
Methods of diagnosis
GeneXpert MTB/RIF assay	181 (79.4)	61	57.2–64.8	32	30.5–33.5
Line probe assay	34 (14.9)	88	86.9–89.1	28	17.3–38.7
Culture	13 (5.7)	76	40.7–111.2	55	43.4–66.6
Resistance type
Rifampicin resistant (RR)	223 (97.8)	61	34–92	34	28–57
Multidrug resistance (MDR)	83 (32.4)	82	56–93	34	28–61
HIV test result
Positive	34 (14.9%)	70	-	35	31–54
Negative	194 (85.1%)	61	34–91	31	28–55
Cotrimoxazole prophylaxis for HIV positives
Yes	28 (82.4)	86	-	34	30–49
No	6 (17.6)	35	22–46	46	-
Drug adverse effect
Yes	23 (10.1)	69	35–92	37	26–69
No	205 (89.9)	61	34–93	34	29–54
History of cigarette smoking
Yes	11 (4.8)	62	22–90	31	23–62
No	217 (95.2)	61	35–93	34	29–54
Body mass index at the beginning of treatment
<18.5 kg/m^2	159 (69.7)	63	34–111	34	29–56
≥18.5 kg/m^2	69 (30.3)	60	47–86	31	28–53
Chest radiographic finding			<0.001
Unitary lung cavity	23 (10.1)	34	23–62	34	26–50
Bilateral lung cavity	9 (3.9)	64	30–89	35	29–64
Abnormality without cavity	64 (28.1)	67	35–91	34	28–56
Massive effusion	11 (4.8)	49	38–88	34	31–49
Other	121 (53.1)	61	44–116	31	28–54
Any co-infection
Yes	12 (5.3)	43	30–56	45	-
No	216 (94.7)	62	35–92	32	28–54
Any chronic disease
Yes	4 (1.8)	61	-	30	-
No	224 (98.2)	61	34–92	34	28–54
History of steroid use
Yes	7 (3.1)	80	43–89	60	19–89
No	106 (46.5)	60	37–111	31	28–54
Unknown	115 (50.4)	63	34–92	34	28–54
Treatment outcome
Cured	192 (84.2)	61	35–90	31	28–54
Completed	10 (4.4)	107	31–118	46	31–116
Failed	7 (3.1)	119	98–130	34	34–36
Died	19 (8.3)	32	26–58	35	26–63

Table 3 Time to Sputum Smear and Culture Conversion of Drug-Resistant Tuberculosis Patients Following Treatment in Oromia Regional State Hospitals from 2012 to 2017, Oromia, Ethiopia

Variables	Proportion of Smear and Culture Conversion at Different Months			Median Time to Smear and Culture Conversion
	2 Months	4 Months	6 Months	Days	Inter-Quartile Range (Q1–Q3)
Sputum culture conversion	46.9%	82.5%	89%	61	34.3–92.8
Sputum smear conversion	81.6%	94.5%	94.9%	34	28–54

Table 4 Test of Equality of Survival Distribution Among Drug-Resistant Tuberculosis Patients Following Treatment in Oromia Regional State Hospitals from 2012 to 2017, Oromia, Ethiopia

Characteristics		Median Time to Culture Conversion	Log-Rank (Mantel-Cox) x^2	Df	P-value
Sex	Male	65	1	1	0.3
	Female	58
Age	<18 years	31	15.6	4	0.004*
	19–24 years	61
	25–30 years	61
	31–40 years	86
	≥41 years	61
Residence	Urban	60	1.6	1	0.24
	Rural	64
HIV status	Positive	70	1.3	1	0.2
	Negative	61
Started cotrimoxazole prophylaxis	Yes	86	13.1	1	<0.001*
	No	35
Drug adverse effect	Yes	69	0.02	1	0.8
	No	61
Smoking	Yes	62	0.2	1	0.6
	No	61
Body mass index	≤18 kg/m^2	67	7.4	1	0.006*
	>18 kg/m^2	58
Chest radiography finding	Unitary lung cavity	34	19.4	4	0.001*
	Bilateral lung cavity	64
	Abnormality without cavity	67
	Massive effusion	49
	Others^b	61
History of steroid use	Yes	80	0.3	2	0.8
	No	60
	Unknown	63

Notes: *Significant at p<0.05. ^bChest X-ray with no interpretation by the radiologist.

Table 5 Predictors of Time to Culture Conversion Among Drug-Resistant Tuberculosis Patients Following Treatment in Oromia Regional State Hospitals from 2012 to 2017, Oromia, Ethiopia

Characteristics	Sputum Culture Conversion Rate After Four Month of Treatment Initiation (%)	CHR (95% CI)	AHR^a (95% CI)	P-value
Resistance type
Rifampicin resistant	82.2	1	1	–
Multi-drug resistant	82.7	0.8 (0.6–1.1)	0.6 (0.08–4.5)	0.6
Body mass index at the beginning of treatment
<18.5 kg/m^2	79.2	0.8 (0.6–1.1)	0.4 (0.02–2.4)	0.1
≥18.5 kg/m^2	89.9	1	1	–
Chest radiographic finding
Unitary lung cavitations	100	1	1	–
Bilateral lung cavitations	88.9	0.4 (0.2–1.1)	0.7 (0.3–1.7)	0.5
Abnormality without cavitations	87.5	0.4 (0.2–0.7)	0.5 (0.2–0.9)	0.02*
Massive effusion	81.8	0.4 (0.2–0.9)	0.4 (0.1–0.9)	0.03*
Others^b	76	0.3 (0.2–0.5)	0.3 (0.1–0.5)	<0.001*
Any chronic disease
Yes	75	0.9 (0.2–2.9)	1.2 (0.06–3.2)	0.9
No	82.6	1	1	–
History of steroid use
Yes	100	1	1	-
No	80.2	0.7 (0.3–1.7)	1.6 (0.6–4.2)	0.3
Unknown	83.5	0.8 (0.3–1.7)	1.1 (0.4–2.5)	0.8

Notes: *Significant at p<0.05. ^aAdjusted for age, sex, registration group, and HIV status. ^bChest x-ray with no interpretation by the radiologist.

Abbreviations: CHR, crude hazard ratio; AHR, adjusted hazard ratio.