Salient beliefs and intention to use pre-exposure prophylaxis among pregnant and breastfeeding women in Zambia: Application of the Theory of Planned Behaviour

Figures & data

Table 1. Characteristics of study participants (n = 389).

Characteristic	Total n (%)
Age in years, median (IQR)	26 (22–30)
Age group (years)
15–24	161 (41.4)
25–34	181 (46.5)
35+	47 (12.1)
Marital status
Not married	44 (11.3)
Married (cohabiting with partner)	327 (84.1)
Married (not cohabiting with partner)	18 (4.6)
Education
No formal education	22 (5.7)
Primary	130 (33.4)
Secondary	226 (58.1)
Tertiary	11 (2.8)
Employment status
Not working	269 (69.2)
Employed for wages	27 (6.9)
Self employed	93 (23.9)
Maternal status
Pregnant	172 (44.2%)
Breastfeeding	217 (55.8%)
Lifetime sexual partners
1 partner	119 (30.6)
2–3 partners	179 (46.0)
>4 partners	91 (23.4)
Condom use (past 30 days)
Never	338 (86.9)
Sometimes	36 (9.2)
Always	15 (3.9)
Partner HIV status
Known	318 (81.8)
Unknown	71 (18.2)
HIV risk perception
No risk	158 (40.6)
Low risk	102 (26.2)
Moderate risk	80 (20.6)
High risk	49 (12.6)
PrEP awareness prior to interview
Yes	141 (36.2)
No	248 (63.7)
Source of information about PrEP
Health facility staff	64 (65.3)
Mass media	8 (8.2)
Family member	13 (13.3)
Friends	9 (9.2)
Other	4 (4.1)

Table 2. Self-reported intention, attitude, subjective norms and perceived behavioural control regarding PrEP use and Pearson correlations among the Theory of Planned Behaviour constructs.

TPB construct	Min–Max	Mean^a (Std. Dev.)	Mean^b (Std. Dev)	Mean^c (Std. Dev)	PrEP intention	PrEP attitude	PrEP subjective norms	PrEP perceived behavioural control
PrEP intention	1–7	6.01 (1.36)	5.72 (1.51)	6.24 (1.18)	r = 1	r = 0.37 P < 0.01	r = 0.74 P < 0.01	r = 0.48 P < 0.01
PrEP attitude	1–7	6.65 (0.71)	6.59 (0.78)	6.69 (0.65)	–	r = 1	r = 0.28 P = <0.01	r = 0.41 P < 0.01
PrEP subjective norms	1–7	6.09 (1.51)	5.81 (1.75)	6.31 (1.25)	–	–	r = 1	r = 0.42 P < 0.01
PrEP perceived behavioural control	1–7	6.52 (1.09)	6.44 (1.14)	6.58 (1.05)	–	–	–	r = 1

^a Mean scores and standard deviation among both pregnant and breastfeeding women.

^b Mean scores and standard deviation among pregnant women.

^c Mean scores and standard deviation among breastfeeding women.

Table 3. Unadjusted estimates for intention to use PrEP stratified by maternal status.

	Unadjusted estimates among pregnant women				Unadjusted estimates among breastfeeding women
Predictor variable	β (95% CI)	Std. error	t	p-value	β (95% CI)	Std. error	t	p-value
Attitude	0.55 (0.26–0.83)	0.14	3.82	<0.01	0.83 (0.61–1.04)	0.11	7.56	<0.01
Subjective norms	0.61 (0.52–0.70)	0.05	13.16	<0.01	0.72 (0.64–0.80)	0.04	17.34	<0.01
Perceived behavioural control	0.68 (0.51–0.86)	0.88	7.80	<0.01	0.51 (0.37–0.64)	0.07	7.36	<0.01

Table 4. Unadjusted and adjusted estimates for intention to use PrEP among HIV-negative pregnant and breastfeeding women.

	Model 1 Unadjusted estimates				Model 2 Adjusted estimates^a				Model 3 Adjusted estimates^b
Predictor variable	β (95% CI)	Robust Std. error	t	p-value	β (95% CI)	Robust Std. error	t	p-value	β (95% CI)	Robust Std. error	t	p-value
Attitude	0.70 (0.52–0.88)	0.09	7.77	<0.01	0.24 (0.03–0.45)	0.11	2.23	0.03	0.24 (0.02–0.45)	0.11	2.15	0.03
Subjective norms	0.67 (0.60–0.73)	0.03	21.63	<0.01	0.57 (0.47–0.68)	0.05	10.76	<0.01	0.55 (0.45–0.66)	0.05	10.44	<0.01
Perceived behavioural control	0.60 (0.49–0.71)	0.06	10.86	<0.01	0.21 (0.06–0.36)	0.08	2.75	<0.01	0.21 (0.06–0.36)	0.08	2.82	<0.01
Breastfeeding	0.52 (0.25–0.79)	0.14	3.81	<0.01					0.24 (0.06–0.42)	0.09	2.57	0.01
R-squared					0.60, p<0.01				0.61, p<0.01

^a Model 2 adjusted for the Theory of Planned Behaviour constructs only (attitude, subjective norms and perceived behavioural control).

^b Model 3 adjusted for the Theory of Planned Behaviour constructs and maternal status, alongside key characteristics of study participants (i.e. age, marital status, education, employment status, HIV risk perception).

Data availability statement

The data that support the findings of this study are available from the corresponding author, [TEH], upon reasonable request.