Biomedical subjects

C R Henderson

Publications and source records attributed to C R Henderson.

At least 19 recordsLinked to original sources

PubMed2001

The extent of unlicensed and off-label drug use in the paediatric ward of a district general hospital in Northern Ireland.

Children receive many drugs which are either unlicensed or used outside the licensing terms (off-label prescribing). Children are thereby at greater risk of side-effects. We sought to determine non-licensed drug usage in a non-specialised paediatric unit because previous studies had examined only specialised centres. Drug charts were examined prospectively over two months. Items were compared with product licenses and determined as licensed, unlicensed or off-label usage. Seventy four charts (237 prescriptions) were examined in which 183 (77.2%) drug courses were licensed. The commonest drugs were antipyretics and antibiotics. In 32 children, 8 items (3.4%) were unlicensed and 46 items (19.4%) were off-label prescriptions. The unlicensed prescriptions were mostly anti-emetics and pro-motility drugs. The three commonest off-label prescriptions were bronchodilators, antibiotics and laxatives. Non-licensed drug usage is common in non-specialised wards and therefore probably all levels of paediatric healthcare provision. Governments must re-examine paediatric drug licensing.

Adolescent↗

PubMed2001

Child maltreatment and the early onset of problem behaviors: can a program of nurse home visitation break the link?

This study investigated the relationship between child maltreatment and the early onset of problem behaviors in the Elmira Nurse Home Visitation Program. Participants were predominantly low-income and unmarried mothers and their first-born children who were randomized either to receive over 2 years of home-visitation services by nurses or to be placed in a comparison group. Data were drawn from a follow-up study that took place when the children were 15 years of age. Results demonstrated that, in the comparison group. child maltreatment was associated with significant increases in the number of early onset problem behaviors reported by the youth. For the youth in the nurse-visited group there was no relationship between maltreatment and early onset problem behaviors. We suggest that this finding was due to the effects of the intervention in reducing the number as well as the developmental timing of the maltreatment incidents. Results suggest that prenatal and infancy home visiting by nurses can moderate the risk of child maltreatment as a predictor of conduct problems and antisocial behavior among children and youth born into at-risk families.

Adolescent↗

PubMed2000

Preventing child abuse and neglect with a program of nurse home visitation: the limiting effects of domestic violence.

CONTEXT: Home visitation to families with young children has been promoted as an effective way to prevent child maltreatment, but few studies have examined the conditions under which such programs meet this goal. OBJECTIVE: To investigate whether the presence of domestic violence limits the effects of nurse home visitation interventions in reducing substantiated reports of child abuse and neglect. DESIGN: Fifteen-year follow-up study of a randomized trial. SETTING: Semirural community in upstate New York. PARTICIPANTS: Of 400 socially disadvantaged pregnant women with no previous live births enrolled consecutively between April 1978 and September 1980, 324 mothers and their children participated in the follow-up study. INTERVENTIONS: Families were randomly assigned to receive routine perinatal care (control group; n = 184 participated in follow-up), routine care plus nurse home visits during pregnancy only (n = 100), or routine care plus nurse home visits during pregnancy and through the child's second birthday (n = 116). MAIN OUTCOME MEASURES: Number of substantiated reports over the entire 15-year period involving the study child as subject regardless of the identity of the perpetrator or involving the mother as perpetrator regardless of the identity of the child abstracted from state records and analyzed by treatment group and level of domestic violence in the home as measured by the Conflict Tactics Scale. RESULTS: Families receiving home visitation during pregnancy and infancy had significantly fewer child maltreatment reports involving the mother as perpetrator (P =. 01) or the study child as subject (P =.04) than families not receiving home visitation. The number of maltreatment reports for mothers who received home visitation during pregnancy only was not different from the control group. For mothers who received visits through the child's second birthday, the treatment effect decreased as the level of domestic violence increased. Of women who reported 28 or fewer incidents of domestic violence (79% of sample), home-visited mothers had significantly fewer child maltreatment reports during the 15-year period than mothers not receiving the longer-term intervention (P =.01). However, this intervention did not significantly reduce child maltreatment among mothers reporting more than 28 incidents of domestic violence (21% of sample). CONCLUSIONS: The presence of domestic violence may limit the effectiveness of interventions to reduce incidence of child abuse and neglect. JAMA. 2000;284:1385-1391.

Child Abuse↗

PubMed2000

Enduring effects of nurse home visitation on maternal life course: a 3-year follow-up of a randomized trial.

CONTEXT: A home visitation program using nurses to improve maternal and child outcomes had favorable results in a randomized trial with a primarily white, semirural population. Many of the short-term findings have been replicated with urban blacks, but whether the program will continue to demonstrate effectiveness after its conclusion is uncertain. OBJECTIVE: To determine the effectiveness of a prenatal and infancy home visitation program on the maternal life course of women in an urban environment 3 years after the program ended. DESIGN AND SETTING: Three-year follow-up of a randomized controlled trial of women seen consecutively between June 1990 and August 1991 at an obstetrical clinic in Memphis, Tenn, who were enrolled in a visitation program for 2 years after the birth of their first child. PARTICIPANTS: A cohort of 743 women who were primarily black, were pregnant for less than 29 weeks, had no previous live births, and had at least 2 sociodemographic risk factors (unmarried, <12 years of education, or unemployed). INTERVENTION: An average of 7 (range, 0-18) home visits during pregnancy and 26 (range, 0-71) from birth to the child's second birthday. MAIN OUTCOME MEASURES: Rate of subsequent pregnancy, mean interval between first and second birth, and mean number of months of welfare use. RESULTS: Compared with the control group, women who received home visits by nurses had fewer subsequent pregnancies (1.15 vs 1.34; P=.03), fewer closely spaced subsequent pregnancies (0.22 vs 0.32; P=.03), longer intervals between the birth of the first and second child (30.25 vs 26.60 months; P=.004), and fewer months of using Aid to Families with Dependent Children (32.55 vs 36.19; P=.01) and food stamps (41.57 vs 45.04; P=.005). Compared with the effect of the program while the program was in operation, the effect after it ended was essentially equal for Aid to Families with Dependent Children, greater for food stamps, greater for rates of closely spaced subsequent pregnancies, and smaller for rates of subsequent pregnancy overall. CONCLUSIONS: We found enduring effects of a home visitation program on the lives of black women living in an urban setting. While these results were smaller in magnitude than those achieved in a previous trial with white women living in a semirural setting, the direction of the effects was consistent across the 2 studies.

Black or African American↗

PubMed1999

Effects of ibuprofen and indomethacin on the regional circulation in newborn piglets.

We investigated the effects of clinically comparable doses of ibuprofen and indomethacin on renal, gastrointestinal and cerebral perfusion in newborn piglets, and hypothesized that ibuprofen would have less effect on regional circulation. Animals were randomly assigned to receive ibuprofen (20 mg/kg, n = 8), indomethacin (0.3 mg/kg, n = 7) or vehicle (n = 6). Fluorescent microspheres were injected prior to and at 20, 40, 60, 90 and 120 min after drug administration. Regional blood flow was measured and vascular resistances were calculated. Cardiovascular and respiratory variables were not significantly affected by either study drug or vehicle. Ibuprofen increased renal cortical and medullary resistance by 44 and 52% (p < 0.05). However, ibuprofen had no significant effects on gastrointestinal or cerebral resistance. Indomethacin raised renal cortical and medullary resistance by 66 and 71% at 60 min postinjection, respectively (p < 0.05). Indomethacin increased duodenojejunal, ileal and colon resistance by 97, 102 and 75% at 60 min, respectively (p < 0.05). Indomethacin increased cerebral cortical and cerebellar resistance by 92 and 86% at 90 min (p < 0. 05). While indomethacin and, to a lesser extent, ibuprofen both increase renal vascular resistance, indomethacin vasoconstricts the gastrointestinal and cerebral circulations which are unaffected by ibuprofen.

Animals↗

PubMed1998

Long-term effects of nurse home visitation on children's criminal and antisocial behavior: 15-year follow-up of a randomized controlled trial.

CONTEXT: A program of home visitation by nurses has been shown to affect the rates of maternal welfare dependence, criminality, problems due to use of substances, and child abuse and neglect. However, the long-term effects of this program on children's antisocial behavior have not been examined. OBJECTIVE: To examine the long-term effects of a program of prenatal and early childhood home visitation by nurses on children's antisocial behavior. DESIGN: Fifteen-year follow-up of a randomized trial. Interviews were conducted with the adolescents and their biological mothers or custodial parents. SETTING: Semirural community in New York. PARTICIPANTS: Between April 1978 and September 1980, 500 consecutive pregnant women with no previous live births were recruited, and 400 were enrolled. A total of 315 adolescent offspring participated in a follow-up study when they were 15 years old; 280 (89%) were born to white mothers, 195 (62%) to unmarried mothers, 151 (48%) to mothers younger than 19 years, and 186 (59%) to mothers from households of low socioeconomic status at the time of registration during pregnancy. INTERVENTION: Families in the groups that received home visits had an average of 9 (range, 0-16) home visits during pregnancy and 23 (range, 0-59) home visits from birth through the child's second birthday. The control groups received standard prenatal and well-child care in a clinic. MAIN OUTCOME MEASURES: Children's self-reports of running away, arrests, convictions, being sentenced to youth corrections, initiation of sexual intercourse, number of sex partners, and use of illegal substances; school records of suspensions; teachers' reports of children's disruptive behavior in school; and parents' reports of the children's arrests and behavioral problems related to the children's use of alcohol and other drugs. RESULTS: Adolescents born to women who received nurse visits during pregnancy and postnatally and who were unmarried and from households of low socioeconomic status (risk factors for antisocial behavior), in contrast with those in the comparison groups, reported fewer instances (incidence) of running away (0.24 vs 0.60; P = .003), fewer arrests (0.20 vs 0.45; P = .03), fewer convictions and violations of probation (0.09 vs 0.47; P<.001), fewer lifetime sex partners (0.92 vs 2.48; P= .003), fewer cigarettes smoked per day (1.50 vs 2.50; P= .10), and fewer days having consumed alcohol in the last 6 months (1.09 vs 2.49; P = .03). Parents of nurse-visited children reported that their children had fewer behavioral problems related to use of alcohol and other drugs (0.15 vs 0.34; P = .08). There were no program effects on other behavioral problems. CONCLUSIONS: This program of prenatal and early childhood home visitation by nurses can reduce reported serious antisocial behavior and emergent use of substances on the part of adolescents born into high-risk families.

Adolescent↗

PubMed1997

Long-term effects of home visitation on maternal life course and child abuse and neglect. Fifteen-year follow-up of a randomized trial.

CONTEXT: Home-visitation services have been promoted as a means of improving maternal and child health and functioning. However, long-term effects have not been examined. OBJECTIVE: To examine the long-term effects of a program of prenatal and early childhood home visitation by nurses on women's life course and child abuse and neglect. DESIGN: Randomized trial. SETTING: Semirural community in New York. PARTICIPANTS: Of 400 consecutive pregnant women with no previous live births enrolled, 324 participated in a follow-up study when their children were 15 years old. INTERVENTION: Families received a mean of 9 home visits during pregnancy and 23 home visits from the child's birth through the second birthday. DATA SOURCES AND MEASURES: Women's use of welfare and number of subsequent children were based on self-report; their arrests and convictions were based on self-report and archived data from New York State. Verified reports of child abuse and neglect were abstracted from state records. MAIN RESULTS: During the 15-year period after the birth of their first child, in contrast to women in the comparison group, women who were visited by nurses during pregnancy and infancy were identified as perpetrators of child abuse and neglect in 0.29 vs 0.54 verified reports (P<.001). Among women who were unmarried and from households of low socioeconomic status at initial enrollment, in contrast to those in the comparison group, nurse-visited women had 1.3 vs 1.6 subsequent births (P=.02), 65 vs 37 months between the birth of the first and a second child (P=.001), 60 vs 90 months' receiving Aid to Families With Dependent Children (P=.005), 0.41 vs 0.73 behavioral impairments due to use of alcohol and other drugs (P=.03), 0.18 vs 0.58 arrests by self-report (P<.001), and 0.16 vs 0.90 arrests disclosed by New York State records (P<.001). CONCLUSIONS: This program of prenatal and early childhood home visitation by nurses can reduce the number of subsequent pregnancies, the use of welfare, child abuse and neglect, and criminal behavior on the part of low-income, unmarried mothers for up to 15 years after the birth of the first child.

Adolescent↗

PubMed1997

Effect of prenatal and infancy home visitation by nurses on pregnancy outcomes, childhood injuries, and repeated childbearing. A randomized controlled trial.

CONTEXT: Interest in home-visitation services as a way of improving maternal and child outcomes has grown out of the favorable results of a trial in semirural New York. The findings have not been replicated in other populations. OBJECTIVE: To test the effect of prenatal and infancy home visits by nurses on pregnancy-induced hypertension, preterm delivery, and low birth weight; on children's injuries, immunizations, mental development, and behavioral problems; and on maternal life course. DESIGN: Randomized controlled trial. SETTING: Public system of obstetric care in Memphis, Tenn. PARTICIPANTS: A total of 1139 primarily African-American women at less than 29 weeks' gestation, with no previous live births, and with at least 2 sociodemographic risk characteristics (unmarried, <12 years of education, unemployed). INTERVENTION: Nurses made an average of 7 (range, 0-18) home visits during pregnancy and 26 (range, 0-71) visits from birth to the children's second birthdays. MAIN OUTCOME MEASURES: Pregnancy-induced hypertension, preterm delivery, low birth weight, children's injuries, ingestions, and immunizations abstracted from medical records; mothers' reports of children's behavioral problems; tests of children's mental development; mothers' reports of subsequent pregnancy, educational achievement, and labor-force participation; and use of welfare derived from state records. MAIN RESULTS: In contrast to counterparts assigned to the comparison condition, fewer women visited by nurses during pregnancy had pregnancy-induced hypertension (13% vs 20%; P=.009). During the first 2 years after delivery, women visited by nurses during pregnancy and the first 2 years of the child's life had fewer health care encounters for children in which injuries or ingestions were detected (0.43 vs 0.55; P=.05); days that children were hospitalized with injuries or ingestions (0.03 vs 0.16; P<.001); and second pregnancies (36% vs 47%; P=.006). There were no program effects on preterm delivery or low birth weight; children's immunization rates, mental development, or behavioral problems; or mothers' education and employment. CONCLUSION: This program of home visitation by nurses can reduce pregnancy-induced hypertension, childhood injuries, and subsequent pregnancies among low-income women with no previous live births.

Child Development↗

PubMed1995

Effects of prenatal and infancy nurse home visitation on surveillance of child maltreatment.

OBJECTIVE: To examine the effects of prenatal and infancy nurse home visitation on the surveillance of child abuse and neglect by examining differences in the health, living conditions, and maltreatment characteristics of nurse-visited and comparison children who had been identified as maltreated in the first 4 years of life. DESIGN: Randomized controlled trial. SETTING: Carried out in a semirural community in upstate, New York. Families dispersed throughout 14 other states during 2-year period after children's second birthdays. PARTICIPANTS: 400 primiparous women registered before 30th week of pregnancy, 85% of whom were either teenaged (< 18 years at registration), unmarried, or from Hollingshead social class IV or V. Maltreated subsample consisted of 56 families in which children had a state-verified report of child abuse or neglect during the first 4 years of the children's life. INTERVENTION: Nurse home visitation from pregnancy through the second year of the child's life. MAIN RESULTS: During the two-year period after the program ended, nurse-visited maltreated children lived in homes with fewer observed safety hazards for children; their homes contained more intellectually stimulating toys, games, and reading materials; their mothers were less controlling; and the children paid 87% fewer visits to the physician for injuries or ingestions, and 38% fewer visits to the emergency department. CONCLUSIONS: Children who were identified as maltreated and who were visited by nurses during pregnancy and the first two years of life had less serious expressions of caregiving dysfunction. This is likely to be a reflection, in part, of earlier and more comprehensive detection of child maltreatment on the part of nurse-visited families.

Adolescent↗

PubMed1994

Prevention of intellectual impairment in children of women who smoke cigarettes during pregnancy.

OBJECTIVE: To analyze the influence of a comprehensive program of nurse home visitation on the intellectual functioning of children born to women who smoked cigarettes during pregnancy. DESIGN: Randomized clinical trial. Treatment 1: sensory and developmental screening at ages 1 and 2 years; treatment 2: screening plus free transportation for prenatal and well-child care; treatment 3: screening, transportation, plus prenatal home visitation; treatment 4: screening, transportation, prenatal home visitation, plus postnatal home visitation through the children's second birthdays. SETTING: Semi-rural community in Upstate New York. PARTICIPANTS: 400 families in which the mothers registered before the 30th week of pregnancy and had no previous live births. Eighty-five percent of the mothers were either teenagers, unmarried, or poor. Analysis was limited to whites, who constituted 89% of sample. INTERVENTION: Nurse home visitation during pregnancy (treatments 3 and 4) or during pregnancy and the first 2 years of the child's life (treatment 4). During pregnancy, the nurses helped women improve their health-related behaviors, informal social support, and linkage with needed community services. MAIN FINDINGS: Children born to women who smoked 10 or more cigarettes per day at registration during pregnancy and who were assigned to treatments 3 and 4 had IQs (averaging across the 3rd and 4th years of life) that were 4.86 (95% CI: 0.47, 9.26) points higher after adjustment for covariates than did children born to women who smoked 10+ cigarettes per day and who were assigned to treatments 1 and 2. The positive influence of the home-visiting program on reducing the harmful effect of smoking appears to be due to prenatal visitation. CONCLUSION: Comprehensive prenatal home-visitation services can offset the impairment in intellectual functioning associated with substantial maternal smoking during pregnancy.

Adolescent↗

PubMed1994

Intellectual impairment in children of women who smoke cigarettes during pregnancy.

OBJECTIVE: To examine the relationship between maternal cigarette smoking during pregnancy and children's intellectual functioning during the first 4 years of life. DESIGN: Prospective follow-up of participants in a randomized trial of pregnancy and infancy nurse home visitation. SETTING: Semi-rural community in Upstate New York. PARTICIPANTS: 400 families in which the mothers registered before the 30th week of pregnancy and had no previous live births. Eighty-five percent of the mothers were either teenagers (< 19 years at registration), unmarried, or poor. Analysis limited to whites who comprised 89% of the sample. MAIN RESULTS: Children in the comparison group whose mothers smoked 10 or more cigarettes per day during pregnancy had Stanford-Binet scores at 3 and 4 years of age that were 4.35 (95% CI: 0.02, 8.68) points lower (after controlling for a wide range of variables) than their counterparts whose mothers did not smoke during pregnancy. CONCLUSIONS: The results of this study add to the increasingly consistent evidence that maternal cigarette smoking during pregnancy poses a unique risk for neurodevelopmental impairment among children and provide an additional reason for pregnant women not to smoke cigarettes.

Adolescent↗

PubMed1994

Does prenatal and infancy nurse home visitation have enduring effects on qualities of parental caregiving and child health at 25 to 50 months of life?

OBJECTIVE: To examine, during the 3rd and 4th years of life, the health, development, rates of child maltreatment, and living conditions of children who had been enrolled in a randomized trial of nurse home visitation during pregnancy and first 2 years of their lives. DESIGN: Prospective follow-up of families who had been randomly assigned to nurse-visited and comparison conditions. SETTING: Study conducted in semirural community in upstate New York. Families dispersed among 14 other states during 2-year period after children's second birthdays. PARTICIPANTS: Four hundred women were recruited through a health department antepartum clinic and offices of private obstetricians and were registered before 30th week of pregnancy. All women had no previous live births and 85% were either teenaged (< 18 years at registration), unmarried, or from Hollingshead social classes IV or V. Analysis focused on whites, who comprised 89% of sample. INTERVENTION: Nurse home visitation from pregnancy through second year of the child's life. MAIN RESULTS: There were no treatment differences in the rates of child abuse and neglect or children's intellectual functioning from 25 to 48 months of age. Nurse-visited children, nevertheless, lived in homes with fewer hazards for children; they had 40% fewer injuries and ingestions and 45% fewer behavioral and parental coping problems noted in the physician record; and they made 35% fewer visits to the emergency department than did children in the comparison group. Nurse-visited mothers were observed to be more involved with and to punish their children to a greater extent than were mothers in the comparison group. The functional meaning of punishment differed between the nurse-visited and comparison families. CONCLUSIONS: The program does have enduring effects on certain aspects of parental caregiving, safety of the home, and children's use of the health care system, but it may be necessary to extend the length of the program for families at highest risk to produce lasting reductions in child abuse and neglect.

Adolescent↗

PubMed1993

Effect of prenatal and infancy nurse home visitation on government spending.

A completed series of reports on a randomized trial (N = 400) indicated that, in contrast to comparison services, prenatal and infancy nurse home visitation improved a wide range of maternal and child health outcomes among poor, unmarried, and teenaged women bearing first children in a semirural county in upstate New York. Eighty-nine percent of the sample was white, and all analyses focused on this group. In this article, an analysis of the net cost of the home-visitation program from the perspective of government spending is presented. The average per-family cost of the program in 1980 dollars was $3,246 for the sample as a whole, and $3,133 for low-income families. Treatment differences in government expenditures for Aid to Families with Dependent Children, Food Stamps, Medicaid, and Child Protective Services, minus tax revenues due to maternal employment (also expressed in 1980 dollars), were conceived as government savings. By the time the children were 4 years of age, government savings were $1,772 (95% confidence interval [CI]: -$557, $4,102) for the sample as a whole, and $3,498 (95% CI: $569, $6,427) for low-income families. Within 2 years after the program ended, after discounting, the net cost of the program (program costs minus savings) for the sample as a whole was $1,582 per family. For low-income families, the cost of the program was recovered with a dividend of $180 per family.

Adolescent↗

PubMed1992

Estimation of heterogeneous variances using empirical Bayes methods: theoretical considerations.

Procedures are described to estimate variances when heterogeneity of genetic and residual dispersion parameters exists for some criterion. Genetic and residual variances are considered to follow distributions with either known or unknown parameters. The estimates of variances obtained are weighted averages of the corresponding parameter and of a data-based statistic. Although the techniques presented are largely inspired by Bayesian ideas, the procedures can be given a frequentist interpretation, and the parameters of the prior distributions can be estimated from the data at hand. Techniques are described and illustrated for situations in which animals are related or unrelated across herds. We conjecture that the proposed estimators have smaller mean squared error than those obtained by grouping observations in some way and then applying REML within each group.

Animals↗

PubMed1988

Improving the life-course development of socially disadvantaged mothers: a randomized trial of nurse home visitation.

We evaluated a comprehensive program of prenatal and postpartum nurse home visitation for socially disadvantaged women bearing first children. Eighty-five per cent of the participating women were either teenagers (less than 19 years at registration), unmarried, or of low socioeconomic status. Women were randomly assigned to either nurse home visitation or comparison services (free transportation for prenatal and well-child care and/or sensory and developmental screening for the child). During the first four years after delivery of their first child, in contrast to their counterparts in the comparison group, nurse-visited White women who had not graduated from high school when they registered in the study returned to school more rapidly; nurse-visited, poor, unmarried White women showed an 82 per cent increase in the number of months they were employed, had 43 per cent fewer subsequent pregnancies, and postponed the birth of second children an average of 12 months longer.

Appalachian Region↗

PubMed1986

Preventing child abuse and neglect: a randomized trial of nurse home visitation.

A program of prenatal and infancy home visitation by nurses was tested as a method of preventing a wide range of health and developmental problems in children born to primiparas who were either teenagers, unmarried, or of low socioeconomic status. Among the women at highest risk for care-giving dysfunction, those who were visited by a nurse had fewer instances of verified child abuse and neglect during the first 2 years of their children's lives (P = .07); they were observed in their homes to restrict and punish their children less frequently, and they provided more appropriate play materials; their babies were seen in the emergency room less frequently during the first year of life. During the second year of life, the babies of all nurse-visited women, regardless of the families' risk status, were seen in the emergency room fewer times, and they were seen by physicians less frequently for accidents and poisonings than comparison group babies (P less than or equal to .05 for all findings, except where indicated.) Treatment differences for child abuse and neglect and emergency room visits were more significant among women who had a lower sense of control over their lives.

Adolescent↗

PubMed1986

Improving the delivery of prenatal care and outcomes of pregnancy: a randomized trial of nurse home visitation.

We evaluated a comprehensive program of prenatal and postpartum nurse home visitation. The program was designed to prevent a wide range of health and developmental problems in children born to primiparous women who were either teenagers, unmarried, or of low socioeconomic status. During pregnancy, women who were visited by nurses, compared with women randomly assigned to comparison groups, became aware of more community services; attended childbirth classes more frequently; made more extensive use of the nutritional supplementation program for women, infants, and children; made greater dietary improvements; reported that their babies' fathers became more interested in their pregnancies; were accompanied to the hospital by a support person during labor more frequently; reported talking more frequently to family members, friends, and service providers about their pregnancies and personal problems; and had fewer kidney infections. Positive effects of the program on birth weight and length of gestation were present for the offspring of young adolescents (less than 17 years of age) and smokers. In contrast to their comparison-group counterparts, young adolescents who were visited by nurses gave birth to newborns who were an average of 395 g heavier, and women who smoked and were visited by nurses exhibited a 75% reduction in the incidence of preterm delivery. (P less than or equal to .05 for all findings.)

Birth Weight↗

PubMed1982

Analysis of covariance in the mixed model: higher-level, nonhomogeneous, and random regressions.

The model generally considered in analysis of covariance has all levels of classification factors and interactions fixed, and also covariate regression coefficients fixed. Mixed models are more appropriate in most applications. A summary of estimation and hypothesis testing for analysis of covariance in the mixed model, including the case of random regression coefficients, is presented. Higher-level covariate regressions (i.e., regressions in which, for all levels of a factor or interaction, all observations on the same level have a common covariate value) are discussed. Nonestimability problems that result from defining such covariates at the levels of fixed effects are illustrated. The case of nonhomogeneous covariate regressions in the mixed model is considered in the context of interpreting predicted future differences among levels of a given factor or interaction. Nonhomogeneous regressions complicate interpretations only when they are associated with the contrast(s) of interest among fixed effects in the model. The question of whether the regressions are homogeneous is itself often of substantive interest. Different random regression coefficients associated with the levels of a random effect are also examined.

Analysis of Variance↗