Table 2. Cox proportional hazard regression analysis of discontinuation rates.

					Hazard ratio*
Characteristics	total	Duration	Event	Incidence (1000 P-m)	Crude (95%CI)	p	Adjusted (95%CI)	p
Age
• 18–24	146	3187.75	35	10.98	1.38 (0.89–2.14)	0.146	0.75 (0.45–1.24)	0.257
• 25–49	269	5970.38	48	8.04	1		1
Instruction level
• Less than secondary school	81	1819.08	17	9.35	1.04 (0.61–1.77)	0.897	0.98(0.55–1.76)	0.955
• Completed secondary school	334	7339.05	66	8.99	1		1
Matrimonial Status
• Not married	339	7503.08	64	8.53	0.74(0.44–1.24)	0.254	0.70 (0.41–1.22)	0.214
• Married/partnered	76	1655.05	19	11.48	1		1
Residence
• Military area	94	1865.72	29	15.54	2.08 (1.33–3.27)	0.001	2.28 (1.36–3.81)	0.002
• Non military area	321	7292.41	54	7.40	1		1
SES
• Lowest third	126	2786.62	28	10.05	1.09 (0.65–1.83)	0.732	1.48 (0.83–2.66)	0.186
• Middle third	141	3122.62	25	8.01	0.86 (0.51–1.47)	0.586	0.83 (0.48–1.44)	0.509
• Highest third	148	3248.88	30	9.23	1		1
Number of living children
• ≤ 2	164	3350.76	54	16.12	3.31 (2.11–5.20)	< 0.001	3.64(2.19–6.08)	< 0.001
• 3 or more	251	5807.38	29	4.99	1		1
Contraceptive history
• Ever used injectable or implant	45	1076.15	2	1.86	1		1
• Never used injectable or implant	370	8081.98	81	10.02	5.49 (1.35–22.32)	0.017	4.49 (1.09–18.55)	0.038
Experienced heavy/ prolonged bleeding
• Yes	131	2800.73	39	13.92	2.05 (1.33–3.16)	0.001	1.96 (1.26–3.04)	0.003
• No	284	6357.41	44	6.92	1		1
Method Information Index
• < 3	188	4112.46	49	11.92	1.81 (1.17–2.81)	0.008	2.08 (1.32–3.28)	0.002
• = 3	227	5045.67	34	6.74	1		1
Overall	415	9158.13	83	9.06

*p-m: person-months