Christine V. Newburn-Cook

Impact of pregnancy-induced hypertension on fetal growth

OBJECTIVE The purpose of this study was to evaluate the effect of different types of pregnancy-induced hypertension on fetal growth. STUDY DESIGN A retrospective cohort study was conducted on the basis of 16,936 births from January 1, 1989, through December 31, 1990, by means of data from a population-based perinatal database in Suzhou, China. Pregnancy-induced hypertension was classified as gestational hypertension, preeclampsia, or severe preeclampsia-eclampsia. Univariate and multivariate regression analyses were performed to examine the effect of the various types of pregnancy-induced hypertension on gestational age, preterm birth, birth weight, low birth weight, and intrauterine growth restriction. RESULTS Gestation was 0.6 week shorter in women with severe preeclampsia than in normotensive women (P <.01). However, the risk of preterm birth was not increased with any classification of pregnancy-induced hypertension (for severe preeclampsia: adjusted odds ratio 1.75; 95% confidence interval, 0.88-3.47). After adjustment for duration of gestation and other confounders, preeclampsia and severe preeclampsia increased the risk of intrauterine growth restriction and low birth weight. The adjusted odds ratios of low birth weight were 2.65 (1.73-4.39) for preeclampsia and 2.53 (1.19-4.93) for severe preeclampsia. However, the risk of low birth weight was not increased significantly for gestational hypertension (adjusted odds ratio 1.56 [1.00-2.41]). CONCLUSION Preeclampsia increases the risk of intrauterine growth restriction and low birth weight.

Factors Influencing Childbearing Decisions and Knowledge of Perinatal Risks among Canadian Men and Women

Background: Women age 35 and older account for an increasing proportion of births and are at increased risk of having difficulties conceiving and of delivering a multiple birth, low birth weight infant, and/or preterm infant. Little is known about men’s and women’s understanding of the maternal age related risks to pregnancy.Objectives: 1) To determine the factors influencing the timing of childbearing for non-parenting men and women, 2) to determine knowledge among non-parenting men and women about maternal age-related reproductive risks, the consequences of low birth weight and multiple birth, and issues related to infertility, and 3) to determine characteristics associated with limited knowledge of these reproductive risks.Methods: An age-stratified random sample of individuals, aged 20–45 years and without children, completed a computer-assisted telephone interview from two urban regions of Alberta, Canada (1006 women and 500 men).Results: Factors that influenced timing of childbearing for both men and women included: financial security (85.8%) and partner suitability to parent (80.2%). Over 70% of men and women recognized the direct relationship between older maternal age and conception difficulties. Less than half knew that advanced maternal age increased the risk of stillbirth, caesarean delivery, multiple birth and preterm delivery.Conclusions: Poor understanding of the links between childbearing after age 35, pregnancy complications and increased risk of adverse infant outcomes limits adults’ ability to make informed decisions about timing of childbearing.

Is Older Maternal Age a Risk Factor for Preterm Birth and Fetal Growth Restriction? A SystematicReview

To determine if there was an association between advancing maternal age and adverse pregnancy outcomes (preterm delivery and small-for-gestational-age births), a systematic review was conducted based on a comprehensive search of the literature from 1985 to 2002. Ten studies met the following inclusion criteria: (1) assessed risk factors for preterm birth by subtype (i.e., idiopathic preterm labor, preterm premature rupture of membranes) and small-for-gestational-age (SGA) birth (fetal growth restriction); (2) used acceptable definitions of these outcomes; (3) were published between January 1985 and December 2002; (4) were restricted to studies that have considered preterm birth due to idiopathic preterm labor or premature rupture of membranes or both; (5) were restricted to singleton live births; (6) were conducted in a developed country; and (7) were published in English. The majority of the studies reviewed found that older maternal age was associated with preterm birth. There is insufficient evidence to determine if older maternal age is an independent and direct risk factor for preterm birth and SGA birth, or a risk marker that exerts its influence on gestational age or birth weight or both through its association with age-dependent confounders. Future research is needed to quantify the independent and unconfounded impact of delayed childbearing on neonatal outcomes, as well as to identify the pathways involved.

Inadequate prenatal care and its association with adverse pregnancy outcomes: A comparison of indices

BackgroundThe objectives of this study were to determine rates of prenatal care utilization in Winnipeg, Manitoba, Canada from 1991 to 2000; to compare two indices of prenatal care utilization in identifying the proportion of the population receiving inadequate prenatal care; to determine the association between inadequate prenatal care and adverse pregnancy outcomes (preterm birth, low birth weight [LBW], and small-for-gestational age [SGA]), using each of the indices; and, to assess whether or not, and to what extent, gestational age modifies this association.MethodsWe conducted a population-based study of women having a hospital-based singleton live birth from 1991 to 2000 (N = 80,989). Data sources consisted of a linked mother-baby database and a physician claims file maintained by Manitoba Health. Rates of inadequate prenatal care were calculated using two indices, the R-GINDEX and the APNCU. Logistic regression analysis was used to determine the association between inadequate prenatal care and adverse pregnancy outcomes. Stratified analysis was then used to determine whether the association between inadequate prenatal care and LBW or SGA differed by gestational age.ResultsRates of inadequate/no prenatal care ranged from 8.3% using APNCU to 8.9% using R-GINDEX. The association between inadequate prenatal care and preterm birth and LBW varied depending on the index used, with adjusted odds ratios (AOR) ranging from 1.0 to 1.3. In contrast, both indices revealed the same strength of association of inadequate prenatal care with SGA (AOR 1.4). Both indices demonstrated heterogeneity (non-uniformity) across gestational age strata, indicating the presence of effect modification by gestational age.ConclusionSelection of a prenatal care utilization index requires careful consideration of its methodological underpinnings and limitations. The two indices compared in this study revealed different patterns of utilization of prenatal care, and should not be used interchangeably. Use of these indices to study the association between utilization of prenatal care and pregnancy outcomes affected by the duration of pregnancy should be approached cautiously.

Unexpected: an interpretive description of parental traumas’ associated with preterm birth

BackgroundPreterm birth (PTB) places a considerable emotional, psychological, and financial burden on parents, families, health care resources, and society as a whole. Efforts to estimate these costs have typically considered the direct medical costs of the initial hospital and outpatient follow-up care but have not considered non-financial costs associated with PTB such as adverse psychosocial and emotional effects, family disruption, strain on relationships, alterations in self-esteem, and deterioration in physical and mental health. The aim of this inquiry is to understand parents’ experience of PTB to inform the design of subsequent studies of the direct and indirect cost of PTB. The study highlights the traumatic nature of having a child born preterm and discusses implications for clinical care and further research.MethodThrough interviews and focus groups, this interpretive descriptive study explored parents’ experiences of PTB. The interviews were audiotaped, transcribed, and analyzed for themes. Analysis was ongoing throughout the study and in subsequent interviews, parents were asked to reflect and elaborate on the emerging themes as they were identified.ResultsPTB is a traumatic event that shattered parents’ taken-for-granted expectations of parenthood. For parents in our study, the trauma they experienced was not related to infant characteristics (e.g., gestational age, birth weight, Apgar scores, or length of stay in the NICU), but rather to prolonged uncertainty, lack of agency, disruptions in meaning systems, and alterations in parental role expectations. Our findings help to explain why things like breast feeding, kangaroo care, and family centered practices are so meaningful to parents in the NICU. As well as helping to (re)construct their role as parents, these activities afford parents a sense of agency, thereby moderating their own helplessness.ConclusionThese findings underscore the traumatic nature and resultant psychological distress related to PTB. Obstetrical and neonatal healthcare providers need to be educated about the symptoms of Acute Stress Disorder (ASD) and Posttraumatic Stress Disorder (PTSD) to better understand and support parents’ efforts to adapt and to make appropriate referrals if problems develop. Longitudinal economic studies must consider the psychosocial implications of PTB to in order to determine the total related costs.

A systematic review of the psychometric properties of self-report research utilization measures used in healthcare.

BackgroundIn healthcare, a gap exists between what is known from research and what is practiced. Understanding this gap depends upon our ability to robustly measure research utilization.ObjectivesThe objectives of this systematic review were: to identify self-report measures of research utilization used in healthcare, and to assess the psychometric properties (acceptability, reliability, and validity) of these measures.MethodsWe conducted a systematic review of literature reporting use or development of self-report research utilization measures. Our search included: multiple databases, ancestry searches, and a hand search. Acceptability was assessed by examining time to complete the measure and missing data rates. Our approach to reliability and validity assessment followed that outlined in the Standards for Educational and Psychological Testing.ResultsOf 42,770 titles screened, 97 original studies (108 articles) were included in this review. The 97 studies reported on the use or development of 60 unique self-report research utilization measures. Seven of the measures were assessed in more than one study. Study samples consisted of healthcare providers (92 studies) and healthcare decision makers (5 studies). No studies reported data on acceptability of the measures. Reliability was reported in 32 (33%) of the studies, representing 13 of the 60 measures. Internal consistency (Cronbachs Alpha) reliability was reported in 31 studies; values exceeded 0.70 in 29 studies. Test-retest reliability was reported in 3 studies with Pearsons r coefficients > 0.80. No validity information was reported for 12 of the 60 measures. The remaining 48 measures were classified into a three-level validity hierarchy according to the number of validity sources reported in 50% or more of the studies using the measure. Level one measures (n = 6) reported evidence from any three (out of four possible) Standards validity sources (which, in the case of single item measures, was all applicable validity sources). Level two measures (n = 16) had evidence from any two validity sources, and level three measures (n = 26) from only one validity source.ConclusionsThis review reveals significant underdevelopment in the measurement of research utilization. Substantial methodological advances with respect to construct clarity, use of research utilization and related theory, use of measurement theory, and psychometric assessment are required. Also needed are improved reporting practices and the adoption of a more contemporary view of validity (i.e., the Standards) in future research utilization measurement studies.

Social inequalities in use of prenatal care in Manitoba.

OBJECTIVE Analysis of regional variations in use of prenatal care to identify individual-level and neighbourhood-level determinants of inadequate prenatal care among women giving birth in the province of Manitoba. METHODS Data were obtained from Manitoba Health administrative databases and the 1996 Canadian Census. An index of prenatal care use was calculated for each singleton live birth from 1991 to 2000 (N = 149,291). Births were geocoded into 498 geographic districts, and a spatial analysis was conducted, consisting of data visualization, spatial clustering, and data modelling using Poisson regression. RESULTS We found wide variation in rates of inadequate prenatal care across geographic areas, ranging from 1.1% to 21.5%. Higher rates of inadequate care were found in the inner-city of Winnipeg and in northern Manitoba. After adjusting for individual characteristics, the highest rates of inadequate prenatal care were among women living in neighbourhoods with the lowest average family income, the highest proportion of the population who were unemployed, the highest rates of recent immigrants, the highest percentage of the population reporting Aboriginal status, the highest percentage of single parent families, the highest percentage of the population with fewer than nine years of education, and the highest rates of women who smoked during pregnancy. CONCLUSION Social inequalities exist in the use of prenatal care among Manitoba women, despite there being a universally funded health care system. Regional disparities in rates of inadequate prenatal care emphasize the need for further research to determine specific risk factors for inadequate prenatal care in socioeconomically disadvantaged neighbourhoods, followed by provision of effective targeted services.

Addressing nonresponse bias in postal surveys.

Postal surveys are sometimes thought of as a simple option for collecting data in community-based studies; however, nurse researchers must exercise care in appropriately addressing the issue of nonresponse. In particular, both the reporters and the users of such research should look beyond survey response rates when considering nonresponse bias. This article describes the benefits of using postal surveys in public health nursing research, while noting the various potential sources of survey error. Particular attention is directed to the implications of low survey response rates, including decreased power, increased standard error, and nonresponse bias. The belief that increasing response rates will necessarily reduce nonresponse bias is discussed, with an emphasis on the need to identify the reasons for nonresponse and to be judicious in the use of strategies to reduce nonresponse bias. Common response-enhancement strategies are identified, while noting the potential for these strategies to increase nonresponse bias. Assessment of the presence and magnitude of nonresponse bias is discussed, and techniques for postsurvey data adjustment are noted. The need to consider nonresponse bias in designing all phases of the study is highlighted, and is exemplified with a case study.

Validation of the conceptual research utilization scale: an application of the standards for educational and psychological testing in healthcare.

BackgroundThere is a lack of acceptable, reliable, and valid survey instruments to measure conceptual research utilization (CRU). In this study, we investigated the psychometric properties of a newly developed scale (the CRU Scale).MethodsWe used the Standards for Educational and Psychological Testing as a validation framework to assess four sources of validity evidence: content, response processes, internal structure, and relations to other variables. A panel of nine international research utilization experts performed a formal content validity assessment. To determine response process validity, we conducted a series of one-on-one scale administration sessions with 10 healthcare aides. Internal structure and relations to other variables validity was examined using CRU Scale response data from a sample of 707 healthcare aides working in 30 urban Canadian nursing homes. Principal components analysis and confirmatory factor analyses were conducted to determine internal structure. Relations to other variables were examined using: (1) bivariate correlations; (2) change in mean values of CRU with increasing levels of other kinds of research utilization; and (3) multivariate linear regression.ResultsContent validity index scores for the five items ranged from 0.55 to 1.00. The principal components analysis predicted a 5-item 1-factor model. This was inconsistent with the findings from the confirmatory factor analysis, which showed best fit for a 4-item 1-factor model. Bivariate associations between CRU and other kinds of research utilization were statistically significant (p < 0.01) for the latent CRU scale score and all five CRU items. The CRU scale score was also shown to be significant predictor of overall research utilization in multivariate linear regression.ConclusionsThe CRU scale showed acceptable initial psychometric properties with respect to responses from healthcare aides in nursing homes. Based on our validity, reliability, and acceptability analyses, we recommend using a reduced (four-item) version of the CRU scale to yield sound assessments of CRU by healthcare aides. Refinement to the wording of one item is also needed. Planned future research will include: latent scale scoring, identification of variables that predict and are outcomes to conceptual research use, and longitudinal work to determine CRU Scale sensitivity to change.

The Content of Prenatal Care and Its Relationship to Preterm Birth in Alberta, Canada

Prenatal care is universally acknowledged as the hallmark of preventive care for pregnant women, and it is commonly assumed to have a positive influence on birth outcomes. The results of studies that have examined the impact of prenatal care on adverse birth outcomes, however, have been equivocal. These investigations have focused primarily on initiation of prenatal care and its timing, and not on the content of care received. Using data obtained from maternal self-reports and an electronic perinatal database, we examined the relationship between selected components of prenatal care (i.e., medical management, health education, and health advice) and the birth of a preterm infant. We found that health care providers are meeting the clinical guidelines for the medical management of pregnancy, but they are not adequately meeting pregnant womens needs for health education and advice. We found no association between the content of prenatal care and the birth of a preterm infant. Prenatal care must focus more on providing health education and advice to pregnant women.