Table 3. Multiple regression coefficients (standard errors) relating natural log-transformed CD4 counts to explanatory variables after stratification by HIV infection status.

Category	Subcategory	HIV-negative (n = 3683)	p-value1	HIV-positive (n = 1310)	p-value1
Sex	Male	Ref.	<0.001	Ref.	<0.001
	Female	0.172 (0.014)***		0.168 (0.044)***
Age group	15–24	Ref.	0.009	Ref.	<0.001
	25–34	0.003 (0.021)		−0.142 (0.049)**
	35–44	0.019 (0.024)		−0.276 (0.055)***
	45–54	0.04 (0.023)		−0.124 (0.066)
	55–64	0.071 (0.025)**		−0.280 (0.09)***
	65+	−0.013 (0.024)		−0.11 (0.153)
ART	no	–		Ref.	<0.001
	yes	–		−0.248 (0.062)***
ART duration (per year)		–		0.1 (0.02)***	<0.001
Place of residence	rural	Ref.	0.117	Ref.	0.060
	peri-urban	−0.024 (0.014)		0.071 (0.039)
	urban	0.021 (0.031)		0.121 (0.055)*
Wealth index	poorest quintile	Ref.	0.247		0.417
	2nd quintile	−0.013 (0.02)		0.007 (0.066)
	3rd quintile	−0.005 (0.021)		−0.031 (0.065)
	4th quintile	0.01 (0.022)		−0.096 (0.066)
	richest quintile	−0.044 (0.024)		−0.007 (0.074)
	unknown	−0.003 (0.025)		−0.076 (0.074)
Education	none	Ref.	0.707	Ref.	0.025
	primary	0.01 (0.028)		−0.012 (0.087)
	higher primary	−0.02 (0.026)		−0.008 (0.08)
	high school	−0.022 (0.024)		−0.071 (0.071)
	tertiary	−0.021 (0.039)		−0.262 (0.098)**
	unknown	−0.032 (0.025)		0.033 (0.076)
TB	no	Ref.	0.420		0.606
	yes	−0.036 (0.045)		−0.029 (0.057)
High blood pressure	no	Ref.	0.158		0.337
	yes	0.026 (0.018)		−0.055 (0.057)
Other chronic diseases	no	Ref.	0.780		0.006
	yes	−0.007 (0.024)		0.128 (0.046)**
BMI	normal	Ref.	0.026		0.255
	overweight	−0.006 (0.019)		0.025 (0.046)
	obese	0.033 (0.02)		0.104 (0.053)
	unknown	0.038 (0.015)		0.048 (0.044)
Sample processing delay	within 2 days	Ref.	<0.001		0.050
	2 days or more	−0.122 (0.016)***		−0.087 (0.044)*

Abbreviations: Ref. – reference, ***p<0.001, **p<0.01, *p<0.05.

¹p-values for variables with multiple categories correspond to a Wald-test that all subcategory coefficients are zero.