Table 4.

Summary associations with incident death among thalassemia patients

Variables	HR (95% CI)	p-value	Adjusted HR (95% CI)1	p-value
Age of diagnosis	0.99 (0.98, 0.99)	<0.001	1.00 (1.00, 1.00)	0.89
Age of starting chelation	1.00 (0.99, 1.00)	<0.001	1.00 (1.00, 1.00)	0.93
Type of thalassemia
Sickle beta thalassemia	1.00 (reference)		1.00 (reference)
Major	4.22 (1.05, 17.01)	0.04	2.40 (0.14, 40.00)	0.53
Intermediate	0.77 (0.18, 3.27)	0.70	1.20 (0.15, 9.60)	0.84
Not defined	7.90 (1.92, 33.00)	0.004	3.80 (0.52, 28.40)	0.18
Residence
Tehran	1.00 (reference)		1.00 (reference)	-
Sari (Mazandaran)	3.30 (2.59, 4.25)	<0.001	0.60 (0.20, 2.10)	0.48
Hormozgan	4.00 (2.99, 5.48)		5.30 (3.10, 9.05)	<0.001
Iranshahr	5.40 (3.20, 9.18)		5.70 (2.60, 12.00)	<0.001
Zahedan	6.20 (4.33, 9.03)		5.20 (2.80, 9.60)	<0.001
Gender
Women	1.00 (reference)		1.00 (reference)
Men	1.40 (1.17, 1.81)	0.001	1.20 (0.82, 1.70)	0.31
Education level
Illiterate	2.49 (1.09, 5.66)	0.03	0.80 (0.23, 3.20)	0.84
< Diploma	3.80 (2.36, 6.19)	<0.001	2.30 (1.20, 4.50)	0.01
Diploma2	1.80 (1.09, 3.14)	0.02	1.30 (0.66, 2.68)	0.41
>Diploma	1.00 (reference)		1.00 (reference)	-
Marriage
Married	1.00 (reference)		1.00 (reference)
Single	3.80 (2.52, 5.79)	<0.001	2.80 (1.40, 5.60)	0.002
Divorced	NA	0.90	NA	-

HR, hazard ratio; CI, confidence interval; NA, not applicable (since the corresponding category did not include enough subjects).

¹The multivariate analysis included all variables listed in Table 3. The enter method was selected for estimating the HR.

²Subjects who had 12 years of formal education in Iran.