An Online Calculator to Estimate the Impact of Changes in Breastfeeding Rates on Population Health and Costs.

OBJECTIVE: We sought to determine the impact of changes in breastfeeding rates on population health. MATERIALS AND METHODS: We used a Monte Carlo simulation model to estimate the population-level changes in disease burden associated with marginal changes in rates of any breastfeeding at each month from birth to 12 months of life, and in rates of exclusive breastfeeding from birth to 6 months of life. We used these marginal estimates to construct an interactive online calculator (available at www.usbreastfeeding.org/saving-calc ). The Institutional Review Board of the Cambridge Health Alliance exempted the study. RESULTS: Using our interactive online calculator, we found that a 5% point increase in breastfeeding rates was associated with statistically significant differences in child infectious morbidity for the U.S. population, including otitis media (101,952 cases, 95% confidence interval [CI] 77,929-131,894 cases) and gastrointestinal infection (236,073 cases, 95% CI 190,643-290,278 cases). Associated medical cost differences were $31,784,763 (95% CI $24,295,235-$41,119,548) for otitis media and $12,588,848 ($10,166,203-$15,479,352) for gastrointestinal infection. The state-level impact of attaining Healthy People 2020 goals varied by population size and current breastfeeding rates. CONCLUSION: Modest increases in breastfeeding rates substantially impact healthcare costs in the first year of life.

Suboptimal breastfeeding in the United States: Maternal and pediatric health outcomes and costs.

The aim of this study was to quantify the excess cases of pediatric and maternal disease, death, and costs attributable to suboptimal breastfeeding rates in the United States. Using the current literature on the associations between breastfeeding and health outcomes for nine pediatric and five maternal diseases, we created Monte Carlo simulations modeling a hypothetical cohort of U.S. women followed from age 15 to age 70 years and their children from birth to age 20 years. We examined disease outcomes using (a) 2012 breastfeeding rates and (b) assuming that 90% of infants were breastfed according to medical recommendations. We measured annual excess cases, deaths, and associated costs, in 2014 dollars, using a 2% discount rate. Annual excess deaths attributable to suboptimal breastfeeding total 3,340 (95% confidence interval [1,886 to 4,785]), 78% of which are maternal due to myocardial infarction (n = 986), breast cancer (n = 838), and diabetes (n = 473). Excess pediatric deaths total 721, mostly due to Sudden Infant Death Syndrome (n = 492) and necrotizing enterocolitis (n = 190). Medical costs total $3.0 billion, 79% of which are maternal. Costs of premature death total $14.2 billion. The number of women needed to breastfeed as medically recommended to prevent an infant gastrointestinal infection is 0.8; acute otitis media, 3; hospitalization for lower respiratory tract infection, 95; maternal hypertension, 55; diabetes, 162; and myocardial infarction, 235. For every 597 women who optimally breastfeed, one maternal or child death is prevented. Policies to increase optimal breastfeeding could result in substantial public health gains. Breastfeeding has a larger impact on women's health than previously appreciated.

Disparities in Breastfeeding: Impact on Maternal and Child Health Outcomes and Costs.

OBJECTIVE: To estimate the disease burden and associated costs attributable to suboptimal breastfeeding rates among non-Hispanic blacks (NHBs), Hispanics, and non-Hispanic whites (NHWs). STUDY DESIGN: Using current literature on associations between breastfeeding and health outcomes for 8 pediatric and 5 maternal diseases, we used Monte Carlo simulations to evaluate 2 hypothetical cohorts of US women followed from age 15 to 70 years and their infants followed from birth to age 20 years. Accounting for differences in parity, maternal age, and birth weights by race/ethnicity, we examined disease outcomes and costs using 2012 breastfeeding rates by race/ethnicity and outcomes that would be expected if 90% of infants were breastfed according to recommendations for exclusive and continued breastfeeding duration. RESULTS: Suboptimal breastfeeding is associated with a greater burden of disease among NHB and Hispanic populations. Compared with a NHW population, a NHB population had 1.7 times the number of excess cases of acute otitis media attributable to suboptimal breastfeeding (95% CI 1.7-1.7), 3.3 times the number of excess cases of necrotizing enterocolitis (95% CI 2.9-3.7), and 2.2 times the number of excess child deaths (95% CI 1.6-2.8). Compared with a NHW population, a Hispanic population had 1.4 times the number of excess cases of gastrointestinal infection (95% CI 1.4-1.4) and 1.5 times the number of excess child deaths (95% CI 1.2-1.9). CONCLUSIONS: Racial/ethnic disparities in breastfeeding have important social, economic, and health implications, assuming a causal relationship between breastfeeding and health outcomes.

A cost comparison of unicompartmental and total knee arthroplasty.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty (TKA) in appropriately selected patients. There is a paucity of data comparing hospital resource utilization and costs for UKA versus TKA. METHODS: We retrospectively reviewed 128 patients who underwent UKA or TKA for osteoarthritis by a single surgeon in the 2011 Fiscal Year. Sixty-four patients in each group were matched based on sex, age, race, body mass index, Charlson Comorbidity Index, and insurance type. Clinical data were obtained from medical records while costs were obtained from hospital billing. Bivariate analyses were used to compare outcomes. RESULTS: Both anesthesia and operative time (minutes) were significantly shorter for patients undergoing UKA (125.7 vs. 156.4; p<0.001, and 81.4 vs. 112.2; p<0.001). UKA patients required fewer transfusions (0% vs. 11.0%; p=0.007) and had a shorter hospital stay (2.2 vs. 3.8days; p<0.001). 96% of UKAs were discharged home compared with 75% of TKAs (p<0.001). Hospital direct costs were lower for UKA ($7893 vs. $11,156; p<0.001) as were total costs (hospital direct costs plus overhead; $11,397 vs. $16,243; p<0.001). Supply costs and implant costs were similarly lower for UKA ($701 vs. $781; p<0.001, and $3448 vs. $5006; p<0.001). CONCLUSION: Our data suggest that UKA provides a cost-effective alternative to TKA in appropriately selected patients. As the number of patients with end-stage arthritis of the knee requiring surgical care continues to rise, the costs of caring for these patients must be considered. LEVEL OF EVIDENCE: Level III, case control study.

Hospitalization Among HIV-Infected U.S. Marshals Service Prisoners.

The U.S. Marshals Service (USMS) prisoner population is diverse and includes immigration violators, fugitives that have evaded apprehension, perpetrators of Medicaid fraud, and parole and probation violators. Unlike state and local jails, the USMS has numerous housing options for its prisoners. Given the unique characteristics, federal prisoners' quality of care, and subsequent clinical outcomes, may differ from those of state and local inmates. However, little is known about hospitalization rates and length of stay for HIV-positive USMS prisoners. The purpose of this study is to examine hospitalizations among HIV-infected prisoners in the custody of the USMS.

Impact of Optimized Breastfeeding on the Costs of Necrotizing Enterocolitis in Extremely Low Birthweight Infants.

OBJECTIVE: To estimate risk of necrotizing enterocolitis (NEC) for extremely low birth weight (ELBW) infants as a function of preterm formula (PF) and maternal milk intake and calculate the impact of suboptimal feeding on the incidence and costs of NEC. STUDY DESIGN: We used aORs derived from the Glutamine Trial to perform Monte Carlo simulation of a cohort of ELBW infants under current suboptimal feeding practices, compared with a theoretical cohort in which 90% of infants received at least 98% human milk. RESULTS: NEC incidence among infants receiving ≥98% human milk was 1.3%; 11.1% among infants fed only PF; and 8.2% among infants fed a mixed diet (P = .002). In adjusted models, compared with infants fed predominantly human milk, we found an increased risk of NEC associated with exclusive PF (aOR = 12.1, 95% CI 1.5, 94.2), or a mixed diet (aOR 8.7, 95% CI 1.2-65.2). In Monte Carlo simulation, current feeding of ELBW infants was associated with 928 excess NEC cases and 121 excess deaths annually, compared with a model in which 90% of infants received ≥98% human milk. These models estimated an annual cost of suboptimal feeding of ELBW infants of $27.1 million (CI $24 million, $30.4 million) in direct medical costs, $563 655 (CI $476 191, $599 069) in indirect nonmedical costs, and $1.5 billion (CI $1.3 billion, $1.6 billion) in cost attributable to premature death. CONCLUSIONS: Among ELBW infants, not being fed predominantly human milk is associated with an increased risk of NEC. Efforts to support milk production by mothers of ELBW infants may prevent infant deaths and reduce costs.

Impact of a Centralized Inpatient Hospice Unit in an Academic Medical Center.

OBJECTIVE: Rush University Medical Center (RUMC) and Horizon Hospice opened the first centralized inpatient hospice unit (CIPU) in a Chicago academic medical center in 2012. This study examined if there was a difference in cost or length of stay (LOS) in a CIPU compared to hospice care in scattered beds throughout RUMC. STUDY DESIGN AND METHODS: This retrospective, cross-sectional study compared cost and LOS for patients admitted to the CIPU (n = 141) and those admitted to hospice scattered beds (SBM) throughout RUMC (n = 56). RESULTS: The CIPU patients had a median LOS of 6.0 days versus 2.0 days for SBM patients. CONCLUSIONS: The CIPU patients had longer hospice LOS but lower hospital costs. Academic medical centers may benefit from aggregating hospice beds.

Factors Associated With Hospitalizations Among HIV-Infected Adults in the United States: Review of the Literature.

Although improving health outcomes in human immunodeficiency virus (HIV)-infected persons has been identified as a national priority, little is known about the factors associated with hospitalizations of HIV-infected persons in the highly active antiretroviral therapy (HAART) era. Since the introduction of HAART in 1996, there has been a dramatic increase in the life expectancy of HIV-infected persons. However, aging and the long term use of HIV medications have led to an increased incidence of chronic, non-HIV-related illnesses. To improve patient outcomes, the factors that contribute to co-morbidities in HIV-infected persons need to be identified. As a first step, we will summarize the current literature on causes and contributing factors of hospitalizations in adults infected with HIV in the HAART era.

Long-term outcomes of a postbaccalaureate nurse residency program: a pilot study.

OBJECTIVE: The purpose of this pilot study was to determine what influence a nurse residency program (NRP) has on long-term outcomes including turnover rates, career satisfaction, and leadership development. BACKGROUND: Studies examining short-term outcomes of NRPs have shown positive effects. Long-term studies of NRPs have not been reported. METHODS: This descriptive study surveyed former nurse residents, still employed at the facility. Data were collected by means of a demographic tool and the McCloskey/Mueller Satisfaction Scale, a job satisfaction tool. RESULTS: Although nursing turnover increased past the yearlong residency program, it remained well below the national average. All components of satisfaction were ranked relatively high, but coworker/peer support was most important to job satisfaction. Leadership development in the areas of certification and pursuing an advanced degree increased with longer employment, but hospital committee involvement decreased with successive cohorts. CONCLUSION: Overall, the long-term outcomes of an NRP appear to have benefits to both the organization and the individual.

A perioperative cost analysis comparing single-level minimally invasive and open transforaminal lumbar interbody fusion.

BACKGROUND CONTEXT: Emerging literature suggests superior clinical short- and long-term outcomes of MIS (minimally invasive surgery) TLIFs (transforaminal lumbar interbody fusion) versus open fusions. Few studies to date have analyzed the cost differences between the two techniques and their relationship to acute clinical outcomes. PURPOSE: The purpose of the study was to determine the differences in hospitalization costs and payments for patients treated with primary single-level MIS versus open TLIF. The impact of clinical outcomes and their contribution to financial differences was explored as well. STUDY DESIGN/SETTING: This study was a nonrandomized, nonblinded prospective review. PATIENT SAMPLE: Sixty-six consecutive patients undergoing a single-level TLIF (open/MIS) were analyzed (33 open, 33 MIS). Patients in either cohort (MIS/open) were matched based on race, sex, age, smoking status, medical comorbidities (Charlson Comorbidity index), payer, and diagnosis. Every patient in the study had a diagnosis of either degenerative disc disease or spondylolisthesis and stenosis. OUTCOME MEASURES: Operative time (minutes), length of stay (LOS, days), estimated blood loss (EBL, mL), anesthesia time (minutes), Visual Analog Scale (VAS) scores, and hospital cost/payment amount were assessed. METHODS: The MIS and open TLIF groups were compared based on clinical outcomes measures and hospital cost/payment data using SPSS version 20.0 for statistical analysis. The two groups were compared using bivariate chi-squared analysis. Mann-Whitney tests were used for non-normal distributed data. Effect size estimate was calculated with the Cohen d statistic and the r statistic with a 95% confidence interval. RESULTS: Average surgical time was shorter for the MIS than the open TLIF group (115.8 minutes vs. 186.0 minutes respectively; p=.001). Length of stay was also reduced for the MIS versus the open group (2.3 days vs. 2.9 days, respectively; p=.018). Average anesthesia time and EBL were also lower in the MIS group (p<.001). VAS scores decreased for both groups, although these scores were significantly lower for the MIS group (p<.001). Financial analysis demonstrated lower total hospital direct costs (blood, imaging, implant, laboratory, pharmacy, physical therapy/occupational therapy/speech, room and board) in the MIS versus the open group ($19,512 vs. $23,550, p<.001). Implant costs were similar (p=.686) in both groups, although these accounted for about two-thirds of the hospital direct costs in the MIS cohort ($13,764) and half of these costs ($13,778) in the open group. Hospital payments were $6,248 higher for open TLIF patients compared with the MIS group (p=.267). CONCLUSIONS: MIS TLIF technique demonstrated significant reductions of operative time, LOS, anesthesia time, VAS scores, and EBL compared with the open technique. This reduction in perioperative parameters translated into lower total hospital costs over a 60-day perioperative period. Although hospital reimbursements appear higher in the open group over the MIS group, shorter surgical times and LOS days in the MIS technique provide opportunities for hospitals to reduce utilization of resources and to increase surgical case volume.

Axillary temperatures in full-term newborn infants: using evidence to guide safe and effective practice.

PURPOSE: Although the American Academy of Pediatrics and the American Congress of Obstetricians and Gynecologists recommend obtaining temperature in newborn infants via the axilla, controversy still exists whether to obtain rectal or axillary temperatures. Of concern is the risk of perforating the rectum or colon during rectal temperature-taking. The purpose of this study was to explore the accuracy of electronic thermometer measuring temperature in the axilla compared with the rectum in full-term newborn infants. DESIGN: This was an agreement study involving a purposive sample of newborn infants who were greater than 37 weeks' gestation. The general care nursery was located in a large, urban Midwestern academic medical center, and data collection occurred between May 2010 and August 2010. METHODS: On admission to the general care nursery, both axillary and rectal temperatures were taken using the FasTemp device by Filac Electronic. Axillary temperatures were taken first, followed immediately by rectal temperature. Descriptive statistics, Pearson correlations, and scatter plots were computed. RESULTS: In 69 newborns, the mean difference between rectal and left axilla temperatures was 0.23°C. There was a significant correlation between rectal temperature and the body temperature for the left axilla (r = 0.786; P = .01). CONCLUSIONS: These preliminary data support the use of left axillary temperature measurement in the full-term newborn infant in the first few days of life to provide a safe and accurate alternative to rectal temperatures. CLINICAL RELEVANCE: Nurses caring for newborn infants now have evidence showing that temperature-taking in the left axilla is an alternative to using rectal temperatures, possibly minimizing discomfort and potential risk of perforation.

The institutional cost of acquiring 100 mL of human milk for very low birth weight infants in the neonatal intensive care unit.

BACKGROUND: Human milk from the biologic mother (HM) reduces disease burden and associated costs of care during and after neonatal intensive care unit (NICU) hospitalization for very low birth weight (VLBW; birth weight < 1500 g) infants, when compared to feedings of donor human milk (DHM) or commercial formula (CF). However, compared to DHM and CF, little is known about the institutional cost to acquire HM from the biologic mother. OBJECTIVE: This study aimed to determine the institutional cost of acquiring HM for VLBW infant feedings during the NICU hospitalization. METHODS: This analysis examined 157 maternal pumping records from a prospective cohort study evaluating health outcomes and cost of HM feedings for VLBW infants. The costs for the breast pump rental fee, 1-time pump kit purchase, and disposable food-grade containers for storing expressed HM were evaluated using standard cost analysis techniques. RESULTS: The median cost of acquiring 100 mL of HM varied from $0.51 when mothers pumped ≥ 700 mL daily to $7.93 for those who pumped < 100 mL daily. Mothers who pumped ≥ 100 mL daily had lower acquisition cost compared to both DHM ($14.84/100 mL) and CF ($3.18/100 mL). For mothers who pumped > 100 mL daily, the exact day of pumping where the cost of HM was less expensive than DHM or CF was 4 to 7 days and 6 to 19 days, respectively. CONCLUSION: Human milk from the biologic mother has lower acquisition cost than DHM and CF when mothers provided ≥ 100 mL daily and pumped for a sufficient number of days (range, 4-19). Neonatal intensive care units should prioritize resources to ensure that mothers achieve this daily milk volume.

Cost of morbidities in very low birth weight infants.

OBJECTIVE: To determine the association between direct costs for the initial neonatal intensive care unit hospitalization and 4 potentially preventable morbidities in a retrospective cohort of very low birth weight (VLBW) infants (birth weight <1500 g). STUDY DESIGN: The sample included 425 VLBW infants born alive between July 2005 and June 2009 at Rush University Medical Center. Morbidities included brain injury, necrotizing enterocolitis, bronchopulmonary dysplasia, and late-onset sepsis. Clinical and economic data were retrieved from the institution's system-wide data and cost accounting system. A general linear regression model was fit to determine incremental direct costs associated with each morbidity. RESULTS: After controlling for birth weight, gestational age, and sociodemographic characteristics, the presence of brain injury was associated with a $12048 (P = .005) increase in direct costs; necrotizing enterocolitis, with a $15 440 (P = .005) increase; bronchopulmonary dysplasia, with a $31565 (P < .001) increase; and late-onset sepsis, with a $10055 (P < .001) increase. The absolute number of morbidities was also associated with significantly higher costs. CONCLUSION: This study provides collective estimates of the direct costs incurred during neonatal intensive care unit hospitalization for these 4 morbidities in VLBW infants. The incremental costs associated with these morbidities are high, and these data can inform future studies evaluating interventions aimed at preventing or reducing these costly morbidities.

Improving the use of human milk during and after the NICU stay.

The feeding of human milk (milk from the infant's own mother; excluding donor milk) during the newborn intensive care unit (NICU) stay reduces the risk of costly and handicapping morbidities in premature infants. The mechanisms by which human milk provides this protection are varied and synergistic, and appear to change over the course of the NICU stay. The fact that these mechanisms include specific human milk components that are not present in the milk of other mammals means that human milk from the infant's mother cannot be replaced by commercial infant or donor human milk, and the feeding of human milk should be a NICU priority. Recent evidence suggests that the impact of human milk on improving infant health outcomes and reducing the risk of prematurity-specific morbidities is linked to specific critical exposure periods in the post-birth period during which the exclusive use of human milk and the avoidance of commercial formula may be most important. Similarly, there are other periods when high doses, but not necessarily exclusive use of human milk, may be important. This article reviews the concept of "dose and exposure period" for human milk feeding in the NICU to precisely measure and benchmark the amount and timing of human milk use in the NICU. The critical exposure periods when exclusive or high doses of human milk appear to have the greatest impact on specific morbidities are reviewed. Finally, the current best practices for the use of human milk during and after the NICU stay for premature infants are summarized.

The initial maternal cost of providing 100 mL of human milk for very low birth weight infants in the neonatal intensive care unit.

OBJECTIVES: Human milk (HM) feeding is associated with lower incidence and severity of costly prematurity-specific morbidities compared to formula feeding in very low birth weight (VLBW; <1,500 g) infants. However, the costs of providing HM are not routinely reimbursed by payers and can be a significant barrier for mothers. This study determined the initial maternal cost of providing 100 mL of HM for VLBW infants during the early neonatal intensive care unit (NICU) stay. METHODS: This secondary analysis examined data from 111 mothers who provided HM for their VLBW infants during the early NICU stay. These data were collected during a multisite, randomized clinical trial where milk output and time spent pumping were recorded for every pumping session (n = 13,273). The cost analysis examined the cost of the breast pump rental, pump kit, and maternal opportunity cost (an estimate of the cost of maternal time). RESULTS: Mean daily milk output and time spent pumping were 558.2 mL (SD = 320.7; range = 0-2,024) and 98.7 minutes (SD = 38.6; range = 0-295), respectively. The mean cost of providing 100 mL of HM varied from $2.60 to $6.18 when maternal opportunity cost was included and from $0.95 to $1.55 when it was excluded. The cost per 100 mL of HM declined with every additional day of pumping and was most sensitive to the costs of the breast pump rental and pump kit. CONCLUSIONS: These findings indicate that HM is reasonably inexpensive to provide and that the maternal cost of providing milk is mitigated by increasing milk output over the early NICU stay.

A 2007 survey of extracorporeal life support members: personnel and equipment.

Extracorporeal membrane oxygenation (ECMO) is used to support patients with cardiopulmonary failure in the intensive care unit. The purpose of this study is to determine what professional qualifications, equipment, and tests are used by established ECMO programs registered with the Extracorporeal Life Support Organization (ELSO). A survey link (Survey-Monkey) was e-mailed to the 110 registered ELSO program coordinators. Forty-nine responses were received. A test of binomial portions showed that nurses were more likely to be ECMO providers than respiratory therapists or perfusionists (p < .05). A chi2 test identified a difference in the type of pump (roller or centrifugal) based on patient age (p < .005). The most common monitoring/safety devices were battery back-up (84%), pre- and post-oxygenator pressure (82%), mixed venous oxygen saturation (80%),venous line pressure (76%), blood flowmeter (63%),bubble detector (61%), point-of-care blood gases (59%), and in-line blood gas monitoring (47%). Laboratory tests available included d-dimer (65%), plasma-free hemoglobin (63%), anti-Xa plasma heparin concentration (43%), thromboelastograph (37%), and heparin concentration using protamine titration (35%). This survey of ELSO-registered centers represents an overview of current ECMO practices.

A comparison of the efficiency, efficacy, comfort, and convenience of two hospital-grade electric breast pumps for mothers of very low birthweight infants.

OBJECTIVE: Many mothers of very low birthweight infants are breast pump-dependent for weeks or months and need a breast pump that is efficient, effective, comfortable, and convenient. STUDY DESIGN: This multisite, blinded, randomized clinical trial compared the efficiency, efficacy, comfort, and convenience of the Symphony breast pump (Medela, McHenry, IL) (SBP) to the Classic breast pump (Medela) (CBP) and also compared these same outcome measures for single- and multiphase suction patterns used in the SBP. All 100 mothers initiated lactation with the CBP and were randomized to single- and multiphase suction patterns in the SBP when daily milk output was at least 350 mL/day. Protocol I included 35 mothers who compared each of three suction patterns in the SBP on two separate occasions (six observations) in the neonatal intensive care unit and used the CBP for all other pumpings. Protocol II included 65 mothers who compared single- and multiphase patterns in the SBP for 7 days and then returned to the CBP for 5 days. RESULTS: The onset of milk ejection was quicker (P < 0.05) for the single- versus multiphase patterns in the SBP, suggesting that mothers had become conditioned to the unphysiolologic single-phase pattern in the CBP. However, all other measures of efficiency and efficacy were not significantly different, including milk output at 5-minute intervals. When asked to compare the SBP and the CBP, mothers in Protocol 1 rated the SBP as significantly more efficient, effective, comfortable, and convenient than the CBP (P < 0.05), regardless of the suction pattern in the SBP. Similarly, mothers in Protocol II rated the SBP significantly (P < 0.05) more comfortable than the CBP, regardless of the specific pattern in the SBP. CONCLUSIONS: These findings suggest that the SBP was as efficient and effective as the CBP but was significantly more comfortable to use for pump-dependent mothers of very low birthweight infants.

Comparison of milk output from the right and left breasts during simultaneous pumping in mothers of very low birthweight infants.

PURPOSE: Milk output from the right and left breasts was compared in mothers who were pumping exclusively and had not yet fed their infants at breast. METHODS: Thirty-five mothers of very low birthweight infants established lactation with a hospital grade, electric, dual pump, and recorded milk output separately for each breast during every pumping session from enrollment until completion of the study (mean = 19.8 days) using a standardized milk log. Milk output from each breast was also weighed during six observed milk expressions over a 2-week period during the study. RESULTS: For the observed pumping sessions (n = 210), milk output was greater from the right breast in 65.7% of the sessions. For the milk log data (n = 3099 pumping sessions) milk output was greater from the right breast in 47.6% of the sessions, greater from the left breast in 28.0%, and equal from both breasts in 24.4% of the sessions. The mean difference in milk output between the right and left breasts was 6.6 mL (SD = 12.1) for the observed sessions, and 5.0 mL for the milk log data (SD = 10.9). The mean right-to-left breastmilk output ratio was 1.20 for the observed sessions and 1.17 for the milk log data. The right-to-left breastmilk ratios were not associated with time of day, day of pumping, total milk output, maternal handedness or the breast pump suction pattern. The right-to-left breast differences were associated with parity and breastfeeding experience, with primiparous women and first-time breastfeeders demonstrating the greatest differences. CONCLUSIONS: These findings suggest that differences in the milk output from the right and left breasts are common, and that milk output is often greater from the right breast. The differences appear early in lactation, are not related to total milk output, and are relatively consistent throughout the day and over the first weeks of lactation.