Effect of Support for Low-Income Mothers of Preterm Infants

Duration of mother's milk expression

Months of milk expression via direct breastfeeding or pumping.

Time frame: From NICU admission through to 12 months postpartum

Gestational weight-for-age

Change in sex-specific gestational weight-for-age z-score while admitted to the NICU.

Time frame: Extracted from medical records 1-2 weeks after discharge from the NICU

Gestational length-for-age z-score

Change in sex-specific gestational length-for-age z-score while admitted to the NICU.

Time frame: Extracted from medical records 1-2 weeks after discharge from the NICU

Gestational head circumference

Change in sex-specific gestational head circumference z-score while admitted to the NICU.

Time frame: Extracted from medical records 1-2 weeks after discharge from the NICU

Necrotizing enterocolitis (NEC)

Experienced NEC during NICU stay according to Vermont Oxford Network (VON) definition; criteria: yes/no.

Time frame: Extracted from medical records 1-2 weeks after discharge from the NICU

Late-onset bacterial or fungal sepsis (LOS)

Experienced with LOS during NICU stay according to Vermont Oxford Network (VON) definition; criteria: yes/no.

Time frame: Extracted from medical records 1-2 weeks after discharge from the NICU

NICU Visitation

Proportion of nursing shifts where mother is present in the NICU.

Time frame: From NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks)

Postpartum Bonding

Score of mother-infant bonding assessed inspired by the Postpartum Bonding Questionnaire, where participants rate their agreement of statements on Likert scales ranging from 0 (always) to 5 (never); scores range from 0 to 50, with higher scores indicating more bonding challenges.

Time frame: Measured in the post-discharge survey within 4-8 week of infant discharge

Provision of breast milk (volume)

Milliliters of nursing shift-total enteral intake that is maternal breast milk fed via gavage tube or bottle.

Time frame: From NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks)

Breastfeeding episode

Occurrence of direct breastfeeding episode during each nursing shift.

Time frame: From NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks)

Maternal physical health

Score of self-reported Short Form Health Survey -1 Physical Health Item; assesses participants' perception of their current physical health. Lower score indicates worse perceived physical health.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Maternal mental health (anxiety)

Score of self-reported 10-item Perceived Stress Scale (PSS-10); assesses the perceived stress levels experienced in terms of overstrain, unmanageability, and unpredictability in the past month. Higher score indicates worse outcome.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Maternal mental health (depression)

Score of the Edinburgh Postnatal Depression Scale (EPDS), a 10-item self-report measure of postpartum depression (ranges from 0-30) with a higher score indicating worse depressive symptoms. The EPDS was developed to assist health professionals in detecting mothers suffering from postpartum depression (PPD).

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Reaction Time Attention Network Test-Revised (ANT-R).

Average response time across all trials to assess overall speed of responses. Lower scores indicate faster reaction times and better attentional performance.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks)

Accuracy Performance Attention Network Test-Revised (ANT-R).

Proportion of accurate responses on the ANT-R. Higher scores indicate higher accurate responses.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks)

Reaction Time Psychomotor Vigilance Task

Average reaction time across trials, assessing overall speed and vigilance. Lower scores indicate quicker reaction times and heightened vigilance.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks)

Accuracy Psychomotor Vigilance Task

Percentage of correct responses out of the total number of trials on the Psychomotor Vigilance Task (PVT). Higher scores indicate higher accurate responses.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks)

Happiness

Score on Happiness Indicator from Integrated Values Surveys; assesses the overall and current perceived level of happiness experienced; with a 4-point scale from 0 (Not at all happy) to 3 (Very Happy). Higher score indicates better perceived level of happiness.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Life satisfaction

Score of the Life Satisfaction Scale Item; assesses participants' perception of their current overall life satisfaction; with a 4-point scale from 0 (Very Satisfied) to 3 (Not At All Satisfied), and was reverse-coded such that higher scores indicate better perceived life satisfaction.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Sleep

Score of Sleep Quality Score (SQS) with 7-Day Recall; evaluates the overall quality of sleep. Core components include sleep duration, ease of falling asleep, frequency of waking during the night (excluding bathroom visits), early waking, and sleep refreshment. The respondent marks an integer score from 0 to 10, according to the following five categories: 0 = terrible, 1-3 = poor, 4-6 = fair, 7-9 = good, and 10 = excellent. Higher score indicates better perceived sleep quality.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Routine postpartum care

Number of routine postpartum follow-up visits attended by mom.

Time frame: Measured at post-discharge (4-8 weeks after infant discharge from NICU); 6 months postpartum; 12 months postpartum

Financial distress

Score of financial stress during the NICU stay based on two metrics: difficulty in paying bills and remaining money at the end of the week. Scoring for each question is summed to create an overall financial distress score, ranging from 0 to 8. Higher score indicates higher financial distress.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Financial hardship

Score of financial hardships experienced during the NICU stay, including using up all savings, taking out loans, borrowing from friends, incurring debt, being threatened by eviction, or having a shut-off of an energy utility. Scoring for each question is yes/no and is summed to create an overall score that ranges between 0 and 6.

Time frame: Measured within one week of discharge form the NICU; post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Food insecurity

Score of Food Insecurity Screening Tool; assesses the risk of food insecurity (availability and affordability) in households based on questions derived from the U.S. Household Food Security Survey Module. Response options include: "Often True," "Sometimes True," "Never True". An affirmative response on either item will be considered to be positive for food insecurity.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Housing instability

Number of moves family has made since their child's birth.

Time frame: Measured within one week of discharge form the NICU; post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Housing insecurity

Score on housing insecurity scale; assesses participants' worry that they may not have stable housing in the next 2 months. Likert scales ranging from 0 (not at all worried) to 3 (very worried). Higher scores indicate greater levels of housing insecurity.

Time frame: Measured within one week of discharge form the NICU; post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Transportation insecurity

Score on transportation insecurity item; assesses participants' experience of transportation-related issues affecting their ability to visit the NICU. Likert scales ranging from 0 (never) to 3 (always). Higher scores indicate greater levels of transportation insecurity.

Time frame: Measured biweekly from NICU admission to discharge or 42 weeks corrected gestational age, whichever comes earlier (maximum of 18 weeks); post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Length of stay

The total number of days from infant admission to discharge from the hospital.

Time frame: Measured within one week of discharge form the NICU

Mother readmission between 4-8 weeks post-discharge

Any mother readmission to the hospital after her initial discharge.

Time frame: Measured between 4-8 weeks after discharge of infant from NICU

Baby readmission between 4-8 weeks post-discharge

Any infant readmission to the hospital after initial discharge.

Time frame: Measured between 4-8 weeks after discharge of infant from NICU

Mother emergency department visit post-discharge

The number of emergency department visits by the mother in the postpartum period.

Time frame: Measured at post-discharge survey (4-8 weeks after infant discharge from NICU); 6 months postpartum; 12 months postpartum

Baby emergency department visit weeks post-discharge

The number of emergency department visits by the infant after discharge.

Time frame: Measured at post-discharge survey (4-8 weeks after infant discharge from NICU); 6 months postpartum; 12 months postpartum

Sleep position

Mothers report of exclusive infant supine position to sleep in the last two weeks.

Time frame: Measured between 4-8 weeks after discharge of infant from NICU

Sleep location

Mothers report exclusively using the room-sharing sleep method, where the infant sleeps in the same room as an adult but on a separate crib or sleep surface, without bed-sharing, in the last two weeks.

Time frame: Measured between 4-8 weeks after discharge of infant from NICU

Breastfeeding expression continuation

Mothers report of breastfeeding continuation.

Time frame: Measured between 4-8 weeks after discharge of infant from NICU

Skin-to-skin care knowledge

Mothers report of knowledge about Skin-to-skin (STS) care based on 4 questions. Scored as a count variable that ranges between 0 and 4.

Time frame: Measured within one week of discharge form the NICU

Breastfeeding knowledge

Mothers report of knowledge about breastfeeding based on 7 questions. Scored as a count variable that ranges between 0 and 7.

Time frame: Measured within one week of discharge form the NICU

Perception of hospital experience

Assesses mothers' overall perception of hospital experience and hospital services during their stay, using a scale from 0 (worst hospital possible) to 10 (best hospital possible).

Time frame: Measured between 4-8 weeks after discharge of infant from NICU

Life's Essential 8 (LE8) behavioral cardiovascular health score

Composite score (0-100) based on four behavioral components: diet quality, physical activity, sleep health, and nicotine exposure, scored according to American Heart Association Life's Essential 8 criteria.

Time frame: Measured at pre-discharge; post-discharge (4-8 weeks, where all components are available); 6 months postpartum; 12 months postpartum

Primary care utilization in the postpartum period

Number of visits with a primary care provider for routine or sick care.

Time frame: Measured at post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum

Adherence to recommended care for chronic conditions

Self-reported adherence to recommended postpartum care for chronic conditions (hypertension, diabetes, and mental health), including medication adherence and engagement with healthcare providers for condition management.

Time frame: Measured at post-discharge (4-8 weeks); 6 months postpartum; 12 months postpartum