摘要：Objectives. We examined visit attendance patterns in the Memphis trial of the Nurse–Family Partnership and associations between these patterns and family characteristics, outcomes, and treatment–control differences in outcomes. Methods. We employed repeated measures latent class analysis to identify attendance patterns among the 228 mothers assigned to receive home nurse visits during pregnancy and until the child was aged 2 years, associated background characteristics, outcomes, and treatment–control differences by visit class. Home visits were conducted from June 1990 to March 1994. We collected outcome data from May 1992 to April 1994 and July 2003 to December 2006. Results. We identified 3 visit attendance patterns. High attenders (48%) had the most visits and good outcomes. Low attenders (33%) had the most education and the best outcomes. Increasing attenders (18%) had the fewest completed visits during pregnancy, the poorest intake characteristics, and the poorest outcomes. Treatment–control group differences varied by class, with high and low attenders having better outcomes on some measures than did their control group counterparts. Conclusions. Three patterns were associated with distinct groups of mothers with different long-term outcomes. Further examination and use of patterns to classify mothers and prioritize resources may improve efficiency in the Nurse–Family Partnership. Low visit attendance is a common problem with preventive interventions 1 and occurs across home visitation programs. 2–5 Missed visits are concerning because they are missed opportunities for providers to educate and support families. The positive outcomes intended for these programs are diminished with shorter duration of involvement 4 and less contact time between the family and the visitor. 6 The degree to which low visit attendance is a problem, however, is not easily quantified because there may not be a simple dose–response relationship between visit attendance and outcomes. Missed visits are associated with participant background characteristics and outcomes inconsistently across studies. Some of these inconsistencies may be attributable to differences in goals, target populations, and service providers. Other apparent inconsistencies may result from assumptions of linear or dichotomized relationships, 5,7–10 in which there is some evidence of nonlinear associations. For instance, in the Elmira, New York, and Memphis, Tennessee, trials of the Nurse–Family Partnership (NFP), completing more visits was associated with lower maternal psychological resources in a linear relationship with an index based on mother’s intelligence, mental health, mastery (the extent to which the mother believes she can control her own life outcomes), and self-efficacy 11 as well as a quadratic function with mothers with high and those with low psychological resources both receiving more visits than mothers with average psychological resources. 12 Lower visit attendance has been associated with lower income 8,10 and education 3,8 and worse mother and child health. 10 However, stress, substance abuse, and mental health problems are associated with higher visit attendance. 7 In one study, more social support was associated with lower visit attendance, 7 but in another, being married and living with a partner was associated with higher visit attendance, whereas living alone was associated with lower visit attendance. 3 The relationship between psychosocial characteristics and visit attendance is complex. Completed visits require cooperation between the mother and the nurse; the mother must be available at the scheduled time and the nurse must reach out to build trust and must reschedule missed appointments. Differences in visit patterns may reflect differences in families’ needs, mothers’ abilities to participate, and visitors’ interpretations of those needs. Visitors’ responses to these factors may differ depending on service provider characteristics or the personality match between the mother and nurse. 13 In one program, sites with visitors who delivered the program with more flexibility had higher retention than did other sites, 3 and increasing visitor flexibility increased completed home visits. 2 Visit attendance can be measured in many ways, including time to attrition, number of visits completed, and total contact time. Examining visit patterns over time instead of these aggregate measures may uncover nonlinear relationships and provide insight into the families’ experiences. Visit patterns can indicate if there are common times when families drop out or frequently miss visits or if there are other common trajectories. Previous work identifying attendance patterns focused on programs with a fixed number of visits, 8,14 but home visiting programs often have a variable number, depending on the timing of enrollment. Visit attendance patterns at specific times during an intervention with a variable number of sessions have not been studied, to our knowledge, nor have the relationships between such patterns and outcomes. Identification of distinct visit attendance patterns may help predict which families would benefit from retention efforts and may improve our understanding of complex relationships between dose and outcomes. NFP is an evidence-based home visitation program implemented nationally 15 in which fewer than half of recommended visits were completed in the original trials and in the current national replication of the program. 2,3 NFP starts during pregnancy and recommends visits until the child’s second birthday. 16 Visit frequency varies over time to support relationship development between the nurse and family and to accommodate shifts in maternal and child health and development over this 2.5-year period. 17 Nurses promote improvements in the mothers’ health and parenting behaviors, economic self-sufficiency, and supportive relationships and link mothers with health and community services. 18 Three randomized controlled trials of the NFP model found consistent improvements in a range of outcomes, including children’s home environments, children’s language development, childhood injuries, and the timing of subsequent pregnancies for mothers. 11,19–21 The intervention affected some outcomes for the whole sample and others (including child’s academic achievement) only for children of mothers with low psychological resources (40%–50% of the samples). The effects of NFP depend on engagement of the families with the program in accordance with the visit patterns achieved in the original NFP trials. Because of different levels of family need and engagement, we examined 3 questions: (1) Were there discernible variations in completed visit patterns over the course of the program? (2) Were those variations associated with risk and outcomes? (3) Were there intervention–control group differences in outcomes for the subgroups defined by visit patterns?
