Table 1.

Questionnaire topics and validated source

Topic	Details	Source
Sociodemographics	- Age in years (continuous) - Sub-county of residence (categorical) - Completed primary education (binary) - Parity (continuous) - Electricity in the home (binary) - Any food insecurity in the past month (binary)¹ - Diagnosed with HIV prior to pregnancy (binary)²	Demographic and Health Survey (Kenya National Bureau of Statistics et al., 2015)
Depression	- Major depression (binary):³ eight-item scale	Patient Health Questionnaire Depression Scale (PHQ-8) (Kroenke et al., 2009; Monahan et al., 2009)
Stigma Internal/self-stigma	- Experienced any internal HIV stigma (binary):⁴ six-item scale	Modified self-stigma subscale from People Living with HIV Stigma Index (International Planned Parenthood Federation, 2008)
Anticipated stigma	- Experienced any anticipated HIV stigma (binary):⁵ five-item scale	Adapted from relevant research studies (Siedner et al., 2012; Turan et al., 2011; Weiser et al., 2006)
Relationship satisfaction	Satisfied with relationship (binary)⁶	Investment Model Scale: satisfaction level facet (Rusbult, Martz, & Agnew, 1998)
Intimate Partner Violence	Experienced frequent emotional IPV in current relationship (binary)⁷	Adapted from previous measures of negative and positive interactions/affective support (Schuster, Kessler, & Aseltine, 1990; Turner, Frankel, & Levin, 1983)
	Experienced frequent physical IPV in current relationship (binary)⁸
Intervention exposure	- Intervention group in parent MOTIVATE! study that was not the control group (binary)⁹	Study investigators

Question asks: in the past 4 weeks how often did it happened that there was no food to eat of any kind in your house because of lack of resources to get food (response options: never, rarely, sometimes, or often). Respondents indicating at least rarely were considered to have food insecurity. Reference group: households never experiencing food insecurity the past month

Reference group: diagnosed with HIV during the most recent pregnancy.

A score of 10 or greater indicates major depression

⁴

Response options for six-items are: never, rarely, sometimes, or often. If a participant answered at least rarely to any item, she was considered to have experienced internal stigma. Reference group: participants who reported never experiencing any of the six items.

⁵

Response options for five-items are: strongly disagree, disagree, agree, strongly agree. If a participant answered “agree” or “strongly agree” to any item, she was considered to have experienced anticipated stigma. Reference group: participants who reported disagreeing (or strongly disagreeing) to all items.

⁶

Question asks: How much do you agree with the following statement: I feel satisfied with our relationship (response options: not at all, a little, somewhat, mostly, almost completely, or completely). Respondents indicating at least mostly were considered to have relationship satisfaction. Reference group: respondents indicating somewhat or less agreement.

⁷

Question asks: How often has your partner said cruel or hurtful things to you during a disagreement (all the time, most of the time, more often than not, occasionally, rarely, never). Frequent emotional IPV considered those who report one of the first three response categories. Reference group: occasionally/never/rarely

⁸

Question asks: How often has your partner said cruel or hurtful thing to you during a disagreement (all the time, most of the time, more often than not, occasionally, rarely, never). Frequent emotional IPV considered those who report one of the first three response categories. Reference group: occasionally/never/rarely

⁹

Intervention groups include: community mentor mothers (cMM) only, text messaging reminders only, and cMM + text. Reference group: participants in control group