Incidence and predictors of lost to follow-up among drug-resistant tuberculosis patients at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia: a retrospective follow-up study

Table 5 Bivariable and multivariable Gompertz regression analysis for predictors of time to lost to follow-up among DR-TB patients, University of Gondar Comprehensive Specialized Hospital, September 2010–December 2017, (N = 332)

Variable	Event^a	Censored^b	CHR (95%CI)	AHR (95%CI)
Median Age (IQR)	29 (25, 45)	30 (22, 40)	1.02 (1.00, 1.05)	1.03 (0.99, 1.05)
Sex
Male	20	186	1
Female	16	110	1.34 (0.69, 2.58)
Body mass index (kg/m²)
< 18.5	25	196	1.22 (0.55 2.71)
> =18.50	8	78	1
Housing Condition^c
Homeless	10	36	2.20 (1.06, 4.57)	2.51 (1.15, 5.45)
Having Home	26	222	1	1
Alcohol drink
No	30	249	1
Yes	5	45	0.91 (0.35, 2.35)
Co-morbidity
No	30	247	1
Yes	6	49	1.12 (0.46, 2.68)
Year of treatment initiation^c
< =2012	6	92	1	1
2013–2014	22	106	3.08 (1.25, 7.59)	3.25 (1.30, 8.13)
> =2015	8	98	1.42 (0.49, 4.11)	2.07 (0.71, 5.99)
Base line sputum smear result
Negative	6	42	1
Positive	27	231	0.77 (0.32, 1.87)
Residency
Urban	19	150	1
Rural	17	146	0.97 (0.51, 1.86)
Cigarette smoking
No	32	245	1
Yes	3	51	0.47 (0.14, 1.53)	0.40 (0.12, 1.35)
HIV co-infection
No	27	219	1
Yes	9	75	1.05 (0.49, 2.24)
Number of previous TB treatment
< 2	11	101	1
> =2	25	193	1.10 (0.54, 2.24)
Occupation
Employed	26	183	1
Unemployed	9	108	0.62 (0.29, 1.32)	0.74 (0.32, 1.68)

LR chi² (6) = 17.14 probability > chi² = 0.0088
CHR Crude Hazard ratio, AHR Adjusted Hazard Ratio, CI Confidence Interval
Event^a in this study was patients lost during follow-up; Censored^b was either cured, completed, death, transfer out, still on treatment
The shape parameter gamma was found to be −0.0811245 (95% CI: −0.1407007, −0.0215482) which is negative. This indicates that the hazard of lost to follow-up decreases exponentially with time
^cSignificantly associated variables in both bivariable and multivariable model

ISSN: 1471-2334