TABLE.

Selected Studies Outlining the Resource Utilization and/or Cost Associated With BPD

REFERENCE	YEAR PUBLISHED	POPULATION	TIME HORIZON	RESOURCES	COSTS/CHARGES	NOTES
Patel et al (26)	2016	N=254 VLBW Source: Prospective single center, admitted to the NICU 2008-2012 Country: USA	Birth hospitalization	Although the LOS is not directly reported, the authors do provide a cost per day and thus it could be calculated; additionally, there is a report on breakdown of different services used between the 2 groups (see Table 3 in Patel et al.)	Cost/charges: Costs Currency: US dollars, 2014 Median cost for BPD $269,004 (IQR:204,606-331,552) compared to $117,078 (IQR 90,496-162,017) (P<.001) In an adjusted analysis, BPD increased costs by $41,929 compared to non-BPD patients Source of costs: hospital data and cost accounting system includes direct and indirect hospital costs Facility fees: included Professional fees: included (based on physician payments) Parent costs: not included Other: N/A	Prospective cohort Table 3 of this article by Patel et al provides a detailed description of the total costs and the individual sub-costs (e.g. hospital direct costs, physician costs, and NICU cost per day) Adjustment: propensity score for BPD, race/ethnicity, gender, gestational age, and small for gestational age
Johnson et al (7)	2013	N=425 VLBW Source: Single center Country: USA	Birth hospitalization	LOS: BPD: Mean 94±31 days compared to 46±19 days w/o BPD (P<.001)	Cost/charges: Costs Currency: US dollars, 2009 Mean 103,151±43,482 compared to 44,465±23,300 (P<.001) BPD cost is $31,565 higher compared to no morbidity when adjusted for GA, sex, birthweight, race/ethnicity, and primary payer (P<.001) Source of costs: Hospital data and cost accounting system using direct hospital costs for each billable item Facility fees: included Professional fees: Not included Parent costs: Not included Other: N/A	Adjusted for birthweight, GA, and sociodemographic characteristics
Landry et al (25)	2012	N=3,442 (with BPD=773; RDS without BPD=2,669) Source: Provincial health administrative databases from Quebec (infants born with RDS and/or BPD between 1983-1992) Data was extracted through March 2008 for follow-up Country: Canada	16- to 25-year follow-up (mean duration 19.3 y for BPD and 17.6 y without BPD)	Health-care utilization and costs Table 2 in the article by Landry et al represents the health-care utilization data Hospitalizations: (mean±SD) BPD: 5±7.3 w/o BPD: 2.9±3.3 (P<.0001) ED visits (per subject; mean±SD): BPD: 15.4±18.9 w/o BPD: 12±14.5 (P=.0002)	Cost/charges: Costs Currency: Canadian dollars, 2008 Total cost per person-year (mean±SD): BPD: $13,472±527 w/o BPD: $10,719±625 (P=.02) Pharmaceutical costs (from 1997 only): BPD: $175±88 w/o BPD: $101±23 (P=.06) Source of costs: Administrative data Facility fees: Included Professional fees: Included Parent costs: Not included Other: Pharmaceutical costs	Infants were identified using ICD-9 codes for BPD, RDS, and prematurity. Hospitalization costs were based on estimates from the Canadian Institute of Health Information and Health Canada Higher diagnosis of asthma (11.13 vs 4.55 diagnosis per patient-year; P<.0001) There is no term equivalent comparison group (just former preterm infants with and without BPD) There was also an increased use of respiratory and neurologic/psychiatric drugs in a subset of the cohort with BPD compared to those w/o BPD)
Stroustrup et al (27)	2010	N=9,542,032 hospitalizations (1.53% of which were <1,500 g at birth) Source: NIS HCUP, 1993–2006 Country: USA	Birth hospitalization	LOS and charges	Cost/charges: Charges Currency: US dollars, year of currency not stated There are no exact cost and LOS estimates in the published article, but the authors give % changes over time: 3.9% annual increase (1993–2006) in LOS for patients with BPD; only 2% when adjusted for VLBW incidence (P<.0001) 4.9% annual increase (1993–2006) in charges for patients with BPD; only 2.9% when adjusted for VLBW incidence (P<.0001) Facility fees: Included Professional fees: Not included Parent costs: Not included Other: N/A	NIS samples 20% of US hospital discharges and is weighted to approximate population BPD identified using the ICD-9 code 770.7 Limited to patients <1,500 g birthweight and those who received non-invasive mechanical ventilation or continuous invasive mechanical ventilation ≥96 hours based on procedure codes Both univariate and multivariable analyses performed (4 different model adjustments were done) Goal of the study was to assess trends over time for incidence of BPD, LOS, and charges
Russell et al (6)	2007	N=9,400 (7,100–11,700) with BPD and 204,600 (186,800–222,300) without BPD Source: NIS HCUP, 2001 Country: USA	Birth hospitalization	LOS was determined in this study, but not directly comparing those with BPD to those without (however, there is LOS comparing normal newborns to preterm/low birthweight)	Cost/charges: Costs (charges were converted to costs using cost-to-charge ratios) Currency: US dollars, 2001 (presumed year, not explicitly stated) Mean 116,000 (95% CI=102,200–129,900; median=102,000) for BPD compared to 16,900 (95% CI=15,200–18,600; median=6,300) without BPD Source of costs: Administrative data Facility fees: Included Professional fees: Not included Parent costs: Not included Other: N/A	NIS samples 20% of US hospital discharges and is weighted to approximate population Attempted to minimize the overlap from inter-hospital transfers during the birth admission (80% of births involved no hospital transfer) BPD identified using the ICD-9 code 770.7 All patients who were defined as preterm/low birthweight (<2,500 g) were included in this analysis likely decreasing the mean/median cost of hospitalization in the non-BPD group
Smith et al (8)	2004	N=1,597 (14.9% with BPD) Source: Northern California Kaiser Permanente Medical Care Program, 6 level III facilities (Neonatal Minimal Dataset linked to California birth certificates and Kaiser follow-up); 1995–1999 Country: USA	Rehospitalization in the first year after birth among infants with BPD (born <33 weeks)	Rehospitalization rates LOS is included for the birth hospitalization	Cost/charges: N/A (resources only) Currency: N/A 49% rehospitalization rate in patients with BPD compared to 23% in patients without BPD (P<.0001) Mean number of rehospitalizations per infant was 2.2±1.9 (BPD) vs 1.6±1.1 (w/o BPD) (P=.0012) Mean LOS of 12.7±27.5 days (BPD) vs 6.4±9.4 days (w/o BPD) (P=.0036) Birth hospitalization LOS: 92.8±37.3 days (BPD) vs 38.4±20.6 days (w/o BPD) Source of costs: Administrative data Facility fees: N/A Professional fees: N/A Parent costs: N/A Other: N/A	Limited to those who survived to first birthday, had follow-up care at Kaiser, and did not have any major anomalies Table 1 of the study provides additional information on resource utilization during the birth hospitalization (eg, duration of ventilator and oxygen use; % of comorbidities such as NEC, ROP, and IVH) No risk factors identified among patients with BPD who were and were not readmitted
Greenough et ala (28)	2002	N=235 (88 received supplemental oxygen) Source: Born in 1 of 4 NICUs between July 1994 and July 1997 Country: United Kingdom	Readmissions and primary care use in the first 2 years after birth in infants with BPD (born <32 weeks) discharged with oxygen compared to infants with BPD with no support BPD defined as oxygen dependence beyond 28 days after birth in this study	Outpatient visits, community care, readmissions (resources and costs) Routine health-care visits were not recorded	Cost/charges: Costs, using the NHS website 1999 reference costs) Currency: British pounds, 1999 Readmissions per infant/LOS per infant: Median (range) Home oxygen group (n=88) −2 (0-20)/7 days (0-131) w/o home oxygen group (n=147) −1 (0-20)/3 days (0-282) P<.05, P<.01 Total costs in the 2 years postdischarge: Mean (range) Home oxygen group (n=88) – 6,802 (896–85,831) w/o home oxygen group (n=147) – 4,881 (95–58,444) P<.001 Facility fees: Included Professional fees: Included Parent costs: Not included Other: N/A	Detailed review was performed of postdischarge records in the first 2 years after birth The costs are broken down into the following categories: Primary care total Primary care respiratory related Primary care drugs Hospital drugs Hospital stay Outpatient attendance Of note, these investigators have published 2 other analyses on this cohort: 1)@Pre-school healthcare utilization by home oxygen status (n=190) – Greenough et al, 2006 (24) 2)@School age outcomes by admission status with RSV – Greenough et al, 2009 (29)
Greenough et ala (20)	2001	N= 235 Source: Born in 1 of 4 NICUs between July 1994 and July 1997 Country: United Kingdom	Readmission with proven RSV infection in the first 2 years after birth in infants with BPD (born <32 weeks) BPD defined as oxygen dependence beyond 28 days after birth in this study	Outpatient visits, community care, readmissions (resources and costs) Routine health-care visits were not recorded	Cost/charges: Costs, using the NHS website (1999 reference costs) Currency: British pounds, 1999 Readmission rate per infant: RSV group (n=45) – 5.4 Probably bronchiolitis (n=24) – 2.8 Other respiratory (n=60) – 3.1 Nonrespiratory (n=106) – 0.6 (P<.001 for between-group comparison) Total costs in the 2 years postdischarge: mean (95% CI) RSV group (n=45) – 12,638 (8,041; 17,235) Probably bronchiolitis (n=24) – 6,059 (3,427; 8,690) Other respiratory (n=60) – 5,683 (3427; 6775) Nonrespiratory (n=106) −2,461 (2,074; 2,849) (P<0.001 for between-group comparison) Facility fees: Included Professional fees: Included Parent costs: Not included Other: N/A	Detailed review was performed of postdischarge records in the first 2 years after birth The costs are broken down into the following categories: Primary care total Primary care respiratory related Primary care drugs Hospital drugs Hospital stay Outpatient attendance
McAleese et al (30)	1993	N=59 Source: Dartmouth-Hitchcock Medical Center, 1981–1989; infants with BPD who were discharged with oxygen; data obtained from hospital billing office Country: USA	Birth hospitalization and home oxygen therapy	Birth hospitalization (LOS and cost) Home oxygen therapy cost Financial and emotional stress on the family	Cost/charges: The article is not clear as it appears to use the words ‘charges’ and ‘costs’ interchangeably Currency: US dollars, 1989–1990 Birth hospitalization: Median birth hospitalization duration 120 days (range: 30–772 days) Mean birth hospitalization cost per patient: $197,668 (median $172,817, range $43,364–$864,594) Mean self-pay for hospital bill $14,103 Median out of pocket expenses $1,624 (range $267–$8,017) (travel, lodging, phone bill) Postdischarge: Home oxygen duration median 92 days (range: 9–577 days) Cost of oxygen and related equipment median $2,250 (range: $475–$9,000) Facility fees: Included Professional fees: Included Parent costs: Included (using parent interviews; parental wage losses were included) Other: N/A	Combination of hospital records as well as parental records and regional charges were used Distribution of costs 82% – hospital charges 12% – physician fees 5% – community hospital charges 1% – parental expenses Interviews of parents provided parental expenses during infant hospitalization Financial and emotional impact of home care was assessed via a questionnaire Home oxygen therapy costs were obtained as average charges from suppliers in the region

The table breaks down some of the elements of costs and summarizes the economic burden. BPD=bronchopulmonary dysplasia; ED=emergency department; GA=gestational age; HCUP=Healthcare Cost and Utilization Project; ICD-9=International Classification of Diseases, Ninth Revision; IQR=interquart11e range; IVH=intraventricular hemorrhage; LOS=length of stay; N/A=not available; NEC=necrotizing enterocolitis; NHS= National Health Service; NIS=National Inpatient Sample; RDS=respiratory distress syndrome; ROP=retinopathy of prematurity; RSV=respiratory syncytial virus; VLBW= very low birthweight.

^aRepresents the same cohort of patients with different focus and period of anaiysis.