Nurse Staffing and Veteran Outcomes in the Veterans Health Administration's Community Living Centers.

BACKGROUND: The demand for nursing care is rising in the long-term care setting. Nurse staffing is a crucial measure linked to health care quality measure outcomes. PURPOSE: To assess for associations between nursing hours per patient day (NHPPD) and outcome measures in the Veterans Health Administration Community Living Centers. METHODS: A retrospective data review of NHPPD and quality measures for 134 community living centers was conducted. Linear regression was used to assess for linear associations between average total NHPPD and 6 quality measures. RESULTS: A significant linear association was found between average total NHPPD and falls with major injury ( P = .02) and help with activities of daily living ( P = .01). No associations were found between nurse staffing and 4 other quality measures. CONCLUSIONS: This study adds to the body of literature regarding the impact of nurse staffing on quality measures.

VA Video Connect for Clinical Care in Older Adults in a Rural State During the COVID-19 Pandemic: Cross-Sectional Study.

BACKGROUND: The COVID-19 pandemic has accelerated the need for telehealth at home. Although the Department of Veterans Affairs is a leading provider of telehealth, disparities may exist in reaching older veterans living in rural areas. VA Video Connect (VVC) is a video conferencing app that enables veterans to connect with their health care provider via a secure and private session. OBJECTIVE: The aim of this study was to examine the capability and willingness of older veterans to participate in a VVC visit during the COVID-19 pandemic. METHODS: A cross-sectional study was conducted on older veterans (N=118) at the Central Arkansas Veterans Healthcare System. Participants were interviewed over the phone and responses to the following items were recorded: availability of internet, email, and an electronic device with a camera; veterans' willingness to complete an appointment via a VVC visit; and availability of assistance from a caregiver for those who were unable to participate in a VVC visit alone. RESULTS: Participants' mean age was 72.6 (SD 8.3) years, 92% (n=108) were male, 69% (n=81) were Caucasian, 30% (n=35) were African Americans, and 36% (n=42) lived in a rural location. The majority reported having access to the internet (n=93, 77%) and email service (n=83, 70%), but only 56% (n=67) had a camera-equipped device. Overall, 53% (n=63) were willing and capable of participating in a VVC visit. The availability of internet access was significantly lower in rural compared to nonrural participants (P=.045) and in those with or less than a high school education compared to those who pursued higher education (P=.02). Willingness to participate in the VVC visit was significantly lower in rural compared to nonrural participants (P=.03). Of the participants who reported they were able and willing to partake in a VVC visit (n=54), 65% (n=35) opted for VVC and 35% (n=19) preferred a phone visit. In total, 77% (n=27) of the scheduled VVC visits were successful. CONCLUSIONS: Despite advances in technology, and willingness on the part of health care systems, there are some lingering issues with capability and willingness to participate in video telehealth visits, particularly among older adults residing in rural areas.

Temporary Balloon Occlusion for Hepatic Arterial Flow Redistribution during Yttrium-90 Radioembolization.

This case series describes an approach for radiation segmentectomy-style treatment of hepatic tumors fed by arteries unsuitable for catheterization. The 15-patient cohort (17 cases from 2015 to 2018) included those diagnosed with liver tumors (14 hepatocellular carcinoma, 1 cholangiocarcinoma, 1 renal-cell carcinoma, and 1 metastatic colorectal carcinoma) and chosen for radioembolization via a multimodal approach. In each case, a balloon microcatheter was used to temporarily redistribute intrahepatic flow during infusion for enhanced radioembolic agent delivery to the tumor. A median of 199 Gy was delivered to a median of 3% of total liver volume. Based on modified Response Evaluation Criteria In Solid Tumors, 11 cases had complete responses and 6 had partial responses.

Maternal/Perinatal Outcome in Women with Sickle Cell Disease: A Comparison of Two Time Periods.

OBJECTIVE: To compare pregnancy outcomes in women with sickle cell disease from recent deliveries with a similar group delivered earlier. METHODS: During a 12-year period (2005-2016), data from pregnant women with hemoglobin SS or SC were collected from three university medical centers and compared with earlier studies (1979-2003) involving similar patients. The primary endpoints were maternal complications during pregnancy and newborn outcomes. RESULTS: There were 278 patients in the control group (1979-2003) compared with 150 patients in the study group (2005-2016). Women in the study group were older (P < 0.0001) and of less parity (P =0.0001), and complications of preterm delivery, preeclampsia, and having a transfusion were similar between the two groups (P = 0.45, 0.95, and 0.49, respectively). Pain crises were more common in the study group (P = 0.02) as was cesarean section (P < 0.0001), but there was a reduction in pulmonary complications (P = 0.0002). Maternal mortality was uncommon (control group [N=4] vs study group [N=3], P = 0.40). Newborn statistics revealed a similar gestational age at delivery (37 weeks), and the incidence of intrauterine growth restriction, as well as 5-minute Apgar score <7 did not differ by group (P = 0. 91, 0.85, and 0.16, respectively). Infants in the study group were heavier on average by approximately 220 g (P = 0.02), whereas the neonatal death rate was low (control group [N=1], study group [N=2] P = 0.60). CONCLUSIONS: Recent pregnancy outcome statistics in women with sickle cell disease have not changed through the years. Innovative strategies to improve maternal and newborn outcomes among such patients are needed.

Exploring Implementation of m-Health Monitoring in Postpartum Women with Hypertension.

BACKGROUND: Preeclampsia is a hypertensive disorder in pregnancy where a patients' blood pressure and warning signs of worsening disease need to be closely monitored during pregnancy and the postpartum period. INTRODUCTION: No studies have examined remote patient monitoring using mobile health (m-health) technologies in obstetrical care for women with preeclampsia during the postpartum period. Remote monitoring and m-health technologies can expand healthcare coverage to the patient's home. This may be especially beneficial to patients with chronic conditions who live far from a healthcare facility. MATERIALS AND METHODS: The study was designed to identify and examine the potential factors that influenced use of m-health technology and adherence to monitoring symptoms related to preeclampsia in postpartum women. A sample of 50 women enrolled into the study. Two participants were excluded, leaving a total sample size of 48 women. Users were given m-health devices to monitor blood pressure, weight, pulse, and oxygen saturation over a 2-week period. Nonusers did not receive equipment. The nurse call center monitored device readings and contacted participants as needed. Both groups completed a baseline and follow-up survey. RESULTS: Women who elected to use the m-health technology on average had lower levels of perceived technology barriers, higher facilitating condition scores, and higher levels of perceived benefits of the technology compared with nonusers. Additionally, among users, there was no statistical difference between full and partial users at follow-up related to perceived ease of use, perceived satisfaction, or perceived benefits. DISCUSSION: This study provided a basis for restructuring the management of care for postpartum women with hypertensive disorders through the use of m-health technology. CONCLUSION: Mobile health technology may be beneficial during pregnancy and the postpartum period for women with preeclampsia to closely manage and monitor their blood pressure and warning signs of worsening disease.

Elevated Diastolic Closing Margin Is Associated with Intraventricular Hemorrhage in Premature Infants.

OBJECTIVE: To determine whether the diastolic closing margin (DCM), defined as diastolic blood pressure minus critical closing pressure, is associated with the development of early severe intraventricular hemorrhage (IVH). STUDY DESIGN: A reanalysis of prospectively collected data was conducted. Premature infants (gestational age 23-31 weeks) receiving mechanical ventilation (n = 185) had ∼1-hour continuous recordings of umbilical arterial blood pressure, middle cerebral artery cerebral blood flow velocity, and PaCO2 during the first week of life. Models using multivariate generalized linear regression and purposeful selection were used to determine associations with severe IVH. RESULTS: Severe IVH (grades 3-4) was observed in 14.6% of the infants. Irrespective of the model used, Apgar score at 5 minutes and DCM were significantly associated with severe IVH. A clinically relevant 5-mm Hg increase in DCM was associated with a 1.83- to 1.89-fold increased odds of developing severe IVH. CONCLUSION: Elevated DCM was associated with severe IVH, consistent with previous animal data showing that IVH is associated with hyperperfusion. Measurement of DCM may be more useful than blood pressure in defining cerebral perfusion in premature infants.

The Diastolic Closing Margin Is Associated with Intraventricular Hemorrhage in Premature Infants.

Premature infants are at an increased risk of intraventricular hemorrhage (IVH). The roles of hypotension and hyperemia are still debated. Critical closing pressure (CrCP) is the arterial blood pressure (ABP) at which cerebral blood flow (CBF) ceases. When diastolic ABP is equal to CrCP, CBF occurs only during systole. The difference between diastolic ABP and CrCP is the diastolic closing margin (DCM). We hypothesized that a low DCM was associated with IVH. One hundred eighty-six premature infants, with a gestational age (GA) range of 23-33 weeks, were monitored with umbilical artery catheters and transcranial Doppler insonation of middle cerebral artery flow velocity for 1-h sessions over the first week of life. CrCP was calculated linearly and using an impedance model. A multivariate generalized linear regression model was used to determine associations with severe IVH (grades 3-4). An elevated DCM by either method was associated with IVH (p < 0.0001 for the linear method; p < 0.001 for the impedance model). Lower 5-min Apgar scores, elevated mean CBF velocity, and lower mean ABP were also associated with IVH (p < 0.0001). Elevated DCM, not low DCM, was associated with severe IVH in this cohort.

Application of a Telecolposcopy Program in Rural Settings.

BACKGROUND: Individuals in rural areas are often restricted by the amount of physicians' availability, thus limiting access to healthcare in those settings. INTRODUCTION: While Pap smear screening has increased across the United States, the rural South still reports high rates of cervical cancer and mortality. One solution to improve patient outcomes related to cervical cancer in rural settings is telecolposcopy. MATERIALS AND METHODS: Women with abnormal Pap results or an abnormal visual examination needing an evaluation by colposcopy were referred to a hospital-based telecolposcopy program. Descriptive data are provided that include patients' access to care based on travel time and transportation costs. RESULTS: Over a 15-month time period, 940 unique patients were seen using telecolposcopy. Telecolposcopy was done at eight spoke sites across Arkansas representing patients from 72 of the 75 counties. Data for risk factors that include smoking, first sexual experience, and number of sexual partners in past 12 months and in a lifetime are discussed. Pap results and impression are provided. In addition, avoided transportation costs and travel time have been calculated and included. DISCUSSION: Cervical cancer is important public health concern especially for women residing in rural areas. We were able to demonstrate that our telecolposcopy program has provided sustainability statewide since its inception and that patients are willing to participate. In addition to providing increased access to care, the program also reduced travel time and costs associated with a face-to-face visit. CONCLUSION: Telecolposcopy should be further explored and utilized in rural settings as a way to reduce patient costs and improve cervical cancer outcomes.

Time trends and payer differences in lengths of initial hospitalization for preterm infants, Arkansas, 2004 to 2010.

OBJECTIVE: The objective of this study was to examine the time trend in length of stay (LOS) and explore potential differences in neonatal LOS by insurance type for preterm infants in Arkansas between 2004 and 2010. STUDY DESIGN: There were 18,712 preterm infants included in our analyses. Accelerated failure time models were used to model neonatal LOS as a function of insurance type and discharge year while adjusting for key maternal and infant characteristics, and complication/anomaly indicators. RESULTS: Before adjusting for the complication/anomaly indicators, the LOS for preterm infants delivered to mothers in the Medicaid group was 3.2% shorter than those in the private payer group. Furthermore, each subsequent year was associated with a 1.6% increase in the expected LOS. However, after accounting for complications and anomalies, insurance coverage differences in neonatal LOS were not statistically significant while the trend in LOS persisted at a 0.59% increase for each succeeding year. CONCLUSION: All of the apparent differences in LOS by insurance type and more than half of the apparent increase in LOS over time are accounted for by higher rates of complications among privately insured preterm infants and increasing rates of complications for all surviving preterm infants between 2004 and 2010.

Web Camera Use of Mothers and Fathers When Viewing Their Hospitalized Neonate.

BACKGROUND: Mothers and fathers of neonates hospitalized in a neonatal intensive care unit (NICU) differ in their experiences related to NICU visitation. PURPOSE: To describe the frequency and length of maternal and paternal viewing of their hospitalized neonates via a Web camera. METHODS/SEARCH STRATEGY: A total of 219 mothers and 101 fathers used the Web camera that allows 24/7 NICU viewing from September 1, 2010, to December 31, 2012, which included 40 mother and father dyads. We conducted a review of the Web camera's Web site log-on records in this nonexperimental, descriptive study. FINDINGS/RESULTS: Mothers and fathers had a significant difference in the mean number of log-ons to the Web camera system (P = .0293). Fathers virtually visited the NICU less often than mothers, but there was not a statistical difference between mothers and fathers in terms of the mean total number of minutes viewing the neonate (P = .0834) or in the maximum number of minutes of viewing in 1 session (P = .6924). Patterns of visitations over time were not measured. IMPLICATIONS FOR PRACTICE: Web camera technology could be a potential intervention to aid fathers in visiting their neonates. Both parents should be offered virtual visits using the Web camera and oriented regarding how to use the Web camera. IMPLICATIONS FOR RESEARCH: These findings are important to consider when installing Web cameras in a NICU. Future research should continue to explore Web camera use in NICUs.

Evaluating the effect of hospital and insurance type on the risk of 1-year mortality of very low birth weight infants: controlling for selection bias.

OBJECTIVES: We examined the effect of hospital type and medical coverage on the risk of 1-year mortality of very low birth weight (VLBW) infants while adjusting for possible selection bias. METHODS: The study population was limited to singleton live birth infants having birth weight between 500 and 1500 g with no congenital anomalies who were born in Arkansas hospitals between 2001 and 2007. Propensity score (PS) matching and PS covariate adjustment were used to mitigate selection bias. In addition, a conventional multivariable logistic regression model was used for comparison purposes. RESULTS: Generally, all 3 analytical approaches provided consistent results in terms of the estimated relative risk, absolute risk reduction, and the number needed to treat. Using the PS matching method, VLBW infants delivered at a hospital with a neonatal intensive care unit (NICU) were associated with a 35% relative decrease (95% bootstrap confidence interval, 18.5%-48.9%) in the risk of 1-year mortality as compared with those infants delivered at non-NICU hospitals. Furthermore, our results showed that on average, 16 VLBW infants (95% bootstrap confidence interval, 11-32), would need to be delivered at a hospital with an NICU to prevent 1 additional death at 1 year. However, there was not a difference in the risk of 1-year mortality between VLBW infants born to Medicaid-insured versus non-Medicaid-insured women. CONCLUSIONS: Estimated relative risk of infant mortality was significantly lower for births that occurred in hospitals with an NICU; therefore, greater efforts should be made to deliver VLBW neonates in an NICU hospital.

The WORD: Outcomes of a Behavioral Weight Loss Maintenance Effectiveness Trial in Rural Black Adults of Faith.

OBJECTIVE: Rural black communities bear a disproportionate burden of obesity. To increase reach among underserved groups, community-based weight loss and maintenance interventions are crucial. METHODS: The Diabetes Prevention Program (DPP) was adapted for rural black adults of faith to create The Wholeness, Oneness, Righteousness, Deliverance (WORD) trial, a group-based, community health worker-delivered weight loss intervention. A Weight Loss Only arm (16 sessions) was compared with a Weight Loss + Maintenance arm (16 + 12 sessions) in a cluster randomized controlled trial of 31 churches (n = 440). Weight and related behaviors were assessed at 0, 6, 12, and 18 months. RESULTS: The WORD produced weight loss from baseline to 6 months (percentage body weight change -2.47 [-3.13 to -1.80]). Among those who lost 5% of their baseline weight, there was a statistical trend of lower weight regain in the Weight Loss + Maintenance arm compared with control. Maintenance arm participants reported higher activity at 12 months. There were no between-arm differences at 18 months. CONCLUSIONS: The WORD produced weight loss from baseline to 6 months on par with that produced by other DPP adaptations for black communities, including adaptations using health professionals. Weight regain was also consistent with that reported in prior literature. Continuing sessions as part of the church's mission may foster adoption of DPP-based weight loss programs.

Participant and Caregiver Perspectives on Clinical Research During Covid-19 Pandemic.

BACKGROUND/OBJECTIVES: The COVID-19 pandemic has massively disrupted essential clinical research. Many regulatory organizations have rightfully advocated to temporarily halt enrollment and curtail all face-to-face interactions. Views and opinions of patients and their caregivers are seldom considered while making such decisions. The objective was to study older participants' and their caregivers' perspectives to participate in ongoing clinical research during the COVID-19 pandemic. DESIGN: Cross-sectional. SETTING: VISN-16/Geriatric Research, Education and Clinical Center (GRECC), Department of Veterans Affairs. PARTICIPANTS: Older participants and their caregivers (N = 51) enrolled in ongoing clinical research studies. MEASUREMENTS: Questions about perceptions of safety to attend research visit, the level of panic among the general public, and medical center's preparedness in handling the pandemic. Other questions identified the source of pandemic information and the preference of a phone or in-person visit. RESULTS: Mean age was 69.3 (±9.4) years, 53% were male, 39% were caregivers, and 65% were Caucasian. Majority (78%) of the participants felt safe/very safe attending the scheduled research appointment; 63% felt that the extra screening made them feel safe/very safe; 82% felt that the medical center was prepared/very prepared for the pandemic. Participants split evenly on their preference for phone versus in-person visits. Family members and television news media were the commonly used sources of pandemic information irrespective of their education. Perceptions were influenced by gender and source of information, not by age or education. Females perceived higher level of panic compared to males (P = .02). Those relying on news media felt safer compared to those that relied on family members (P = .008). CONCLUSION: Even though informants felt that the medical center was prepared to handle the pandemic, only half the participants preferred the in-person visit. Pandemic information was obtained from family members or the television news media. Knowing patients' perspectives may help researchers be better prepared for future pandemics. J Am Geriatr Soc 68:E14-E18, 2020.

Cerebral blood flow velocities in extremely low birth weight infants with hypotension and infants with normal blood pressure.

OBJECTIVE: To determine whether extremely low birth weight (ELBW) infants with hypotension have similar cerebral hemodynamics when compared with control subjects with normal blood pressure. We hypothesized that ELBW infants with low or normal blood pressure have similar cerebral blood flow (CBF) velocity. STUDY DESIGN: In this case control study, CBF velocity (with Doppler ultrasound scanning), PCO2, and mean arterial blood pressure (MABP) were continuously monitored twice daily before intensive care procedures. If an infant became hypotensive (MABP < or = gestational age in weeks), additional monitoring was performed for 10 to 20 minutes, before treatment with dopamine. Thirty ELBW infants were enrolled (637 +/- 140 g, 24.2 +/- 1.1 weeks); 15 had hypotension, and 15 were gestational age/birth weight-matched control subjects with normal blood pressure. CBF velocity was compared by use of the Mann-Whitney U test. RESULTS: The groups did not differ significantly in gestational age, birth weight, race, sex, PCO2, Apgar scores, or occurrence of severe intraventricular hemorrhage. There was no difference in mean CBF velocity (P = .934) in infants with hypotension (MABP: 23 [20-24.9] mm Hg) compared with infants with normal blood pressure (MABP: 32.6 [27.5-35.7] mm Hg). CONCLUSION: Despite having hypotension, ELBW infants (before treatment) had similar CBF velocity compared with control subjects with normal blood pressure. On the basis of these results, hypotension may not indicate decreased CBF.

Reach and Adoption of a Randomized Weight Loss Maintenance Trial in Rural African Americans of Faith: The WORD (Wholeness, Oneness, Righteousness, Deliverance).

PURPOSE: There is minimal information regarding the Reach and Adoption of evidence-based weight loss maintenance interventions for African Americans of faith. DESIGN: The WORD (Wholeness, Oneness, Righteousness, Deliverance) was an 18-month, cluster randomized trial designed to reduce and maintain weight loss in African American adults of faith. Participants received the Diabetes Prevention Program adapted core weight loss program for 6 months, and churches were subsequently randomized to 12-month maintenance treatment or control. All participants underwent body weight and associated behavioral and psychosocial assessments at baseline, 6, 12, and 18 months. The current article focuses on assessing Reach and Adoption at baseline and 6 months using the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework. SETTING: Lower Mississippi Delta. PARTICIPANTS: Thirty churches, 61 WORD Leaders (WLs), and 426 participants. INTERVENTION: Group delivered by trained community members (WLs). MEASURES: Body mass index and percentage weight lost from baseline to 6-month follow-up were measured. Reach was assessed at participant, WL, and church levels through calculating participation rates and sociodemographics of each level. Adoption was assessed at church and WL levels. ANALYSIS: Descriptive statistics summarized baseline characteristics of each level. Continuous and categorical end point comparisons were made. RESULTS: Participants' participation rate was 0.84 (n = 437 agreed to participate, n = 519 eligible invited to participate); they were predominantly female, employed, and had a mean age of 49.8. Dropouts by 6 months were younger, had differential marital status, and religious attendance compared with retained participants. Church participation rate was 0.63 (n = 30 enrolled, n = 48 eligible approached) and the majority reported ≤100 active members. The WL participation rate was 0.61 (n = 61 implemented intervention, n = 100 eligible approached); they were primarily female and aged 53.9 (mean). CONCLUSION: Recruitment, engagement, and delivery strategies employed by the WORD show promise of sustained engagement and adoption in other faith-based behavioral weight management programs for African Americans.

Normal pulmonary artery and branch pulmonary artery sizes in children.

To establish standards for pulmonary artery and branch pulmonary artery (PA and BPA) effective diameter (ED) and cross-sectional area (CSA) by using computed tomography (CT) data in children of a wide range of sizes and investigate the roundness of arteries. The ED (average of short and long axes) and CSA for the PA and BPA were measured using 1-mm collimation double-oblique reconstructions. Ordinary least squares regression was used to investigate models with various functional forms that related ED and CSA to patient size. Aspect ratio (AR), the short axis divided by long axis, was measured to evaluate roundness. The ideal diameter derived from CSA measurements was compared to ED, short axis, and long axis measurements. 108 CT examinations were analyzed in children without reason for abnormal PA size who ranged in age from 0 to 18 years (mean, 10.9 years; SD, 5.9 years). Interrater reliability was excellent. Data were modeled using a natural log-transformed response variable and a linear term for height as the independent variable. AR for the PA, right pulmonary artery, and left pulmonary artery measured < 0.9 for 38, 55, and 37%, respectively, indicating that many arteries are not round. Ideal diameter was not significantly different than ED but was for short- and long-axis diameter measurements. Normal ED and CSA for PA and BPA were determined for children of different sizes. Measurements outside of the normal range are consistent with dilatation or stenosis. Single diameter techniques are likely to introduce error.

Impact of a smoke-free hospital campus policy on employee and consumer behavior.

OBJECTIVE: Although smoke-free hospital campuses can provide a strong health message and protect patients, they are few in number due to employee retention and public relations concerns. We evaluated the effects of implementing a clean air policy on employee attitudes, recruitment, and retention; hospital utilization; and consumer satisfaction in 2003 through 2005. METHODS: We conducted research at a university hospital campus with supplemental data from an affiliated hospital campus. Our evaluation included (1) measurement of employee attitudes during the year before and year after policy implementation using a cross-sectional, anonymous survey; (2) focus group discussions held with supervisors and security personnel; and (3) key informant interviews conducted with administrators. Secondary analysis included review of employment records and exit interviews, and monitoring of hospital utilization and patient satisfaction data. RESULTS: Employee attitudes toward the policy were supportive (83.3%) at both institutions and increased significantly (89.8%) at post-test at the university hospital campus. Qualitatively, administrator and supervisor attitudes were similarly favorable. There was no evidence on either campus of an increase in employee separations or a decrease in new hiring after the policy was implemented. On neither campus was there a change in bed occupancy or mean daily census. Standard measures of consumer satisfaction were also unchanged at both sites. CONCLUSION: A campus-wide smoke-free policy had no detrimental effect on measures of employee or consumer attitudes or behaviors.

Changes in school environments with implementation of Arkansas Act 1220 of 2003.

Changes in school nutrition and physical activity policies and environments are important to combat childhood obesity. Arkansas Act 1220 of 2003 was among the first and most comprehensive statewide legislative initiatives to combat childhood obesity through school-based change. Annual surveys of principals and superintendents have been analyzed to document substantial and important changes in school environments, policies, and practices. For example, results indicate that schools are more likely to require that healthy options be provided for student parties (4.5% in 2004, 36.9% in 2008; P

Purposeful selection of variables in logistic regression.

BACKGROUND: The main problem in many model-building situations is to choose from a large set of covariates those that should be included in the "best" model. A decision to keep a variable in the model might be based on the clinical or statistical significance. There are several variable selection algorithms in existence. Those methods are mechanical and as such carry some limitations. Hosmer and Lemeshow describe a purposeful selection of covariates within which an analyst makes a variable selection decision at each step of the modeling process. METHODS: In this paper we introduce an algorithm which automates that process. We conduct a simulation study to compare the performance of this algorithm with three well documented variable selection procedures in SAS PROC LOGISTIC: FORWARD, BACKWARD, and STEPWISE. RESULTS: We show that the advantage of this approach is when the analyst is interested in risk factor modeling and not just prediction. In addition to significant covariates, this variable selection procedure has the capability of retaining important confounding variables, resulting potentially in a slightly richer model. Application of the macro is further illustrated with the Hosmer and Lemeshow Worchester Heart Attack Study (WHAS) data. CONCLUSION: If an analyst is in need of an algorithm that will help guide the retention of significant covariates as well as confounding ones they should consider this macro as an alternative tool.

The effects of hypercapnia on cerebral autoregulation in ventilated very low birth weight infants.

Permissive hypercapnia, a strategy allowing high Pa(CO2), is widely used by neonatologists to minimize lung damage in ventilated very low birth weight (VLBW) infants. While hypercapnia increases cerebral blood flow (CBF), its effects on cerebral autoregulation of VLBW infants are unknown. Monitoring of mean CBF velocity (mCBFv), Pa(CO2), and mean arterial blood pressure (MABP) from 43 ventilated VLBW infants during the first week of life was performed during and after 117 tracheal suctioning procedures. Autoregulation status was determined during tracheal suctioning because it perturbs cerebral and systemic hemodynamics. The slope of the relationship between mCBFv and MABP was estimated when Pa(CO2) was fixed at 30, 35, 40, 45, 50, 55, and 60 mm Hg. A slope near or equal to 0 suggests intact autoregulation, i.e. CBF is not influenced by MABP. Increasing values >0 indicate progressively impaired autoregulation. Infants weighed 905 +/- 259 g and were 26.9 +/- 2.3 wk gestation. The autoregulatory slope increased as Pa(CO2)) increased from 30 to 60 mm Hg. While the slopes for Pa(CO2) values of 30 to 40 mm Hg were not statistically different from 0, slopes for Pa(CO2) > or = 45 mm Hg indicated a progressive loss of cerebral autoregulation. The autoregulatory slope increases with increasing Pa(CO2), suggesting the cerebral circulation becomes progressively pressure passive with hypercapnia. These data raise concerns regarding the use of permissive hypercapnia in ventilated VLBW infants during the first week of life, as impaired autoregulation during this period may be associated with increased vulnerability to brain injury.