SENTINEL1: The largest study to date of US preterm infants 29-35 wGA hospitalized with laboratory-confirmed RSV disease during the 2014-2015 and 2015-2016 RSV seasons1,2

SENTINEL1 identified 1378 infants with community-acquired RSV across both the 2014-2015 and 2015-2016 RSV seasons from 46 hospitals*

*Data were collected from October 1, 2014 through April 30, 2015, and October 1, 2015 through April 30, 2016; results represent data of eligible infants with an RSV-confirmed hospitalization irrespective of enrollment status.

Out of a total of 1398 study-eligible infants identified, 20 who had nosocomial RSV disease were separately analyzed from the 1378 who had community-acquired RSV disease.

Study Design

A multicenter, retrospective and prospective observational study of respiratory syncytial virus (RSV) hospitalizations among US infants born at 29-35 wGA not receiving immunoprophylaxis in the 2014-2015 and 2015-2016 RSV seasons. Infants born at 29-35 wGA (29 weeks, 0 days through 35 weeks, 6 days) who were hospitalized ≥24 hours for laboratory-confirmed RSV disease (index RSVH) that was either community-acquired or nosocomial RSV disease AND who were <12 months of age at the time of index RSVH were included in the study.

Study Objectives

  • Characterize RSV-confirmed hospitalization among US preterm infants born at 29-35 wGA who had not received immunoprophylaxis during the 2014-2015 and 2015-2016 RSV seasons
  • Compare the 2015-2016 season results for the study-eligible identified patient population to those of the 2014-2015 season

Hospital and intensive care unit (ICU) Lengths of Stay (LOS)

In the 2014-2015 RSV season, average hospital and ICU length of stay was high and ranged from 7-10 days*

AVERAGE HOSPITAL LOS

Gestational age Mean hospital LOS, days (SD) Range
29-32 wGA (n=237) 10 (10) 1-67
33-34 wGA (n=283) 9 (12) 1-101
35 wGA (n=182) 7 (11) 1-135

ICU LOS

Gestational age Mean ICU LOS, days (SD) Range
29-32 wGA (n=115) 9 (8) 1-61
33-34 wGA (n=117) 9 (12) 1-91
35 wGA (n=56) 8 (9) 1-59

*702 infants 29-35 wGA hospitalized for community-acquired RSV disease were identified; hospital LOS data were available for 678 of the 702 infants. 288 of the 702 infants were admitted to the ICU; ICU LOS was available for 284 of these infants.

wGA=weeks gestational age; SD=standard deviation

In the 2015-2016 RSV season, average hospital and ICU length of stay was high and ranged from 7-10 days

AVERAGE HOSPITAL LOS

Gestational age Mean hospital LOS, days (SD) Range
29-32 wGA (n=204) 10 (16) 1-188
33-34 wGA (n=288) 8 (10) 1-85
35 wGA (n=184) 8 (11) 1-113

ICU LOS

Gestational age Mean ICU LOS, days (SD) Range
29-32 wGA (n=97) 9 (9) 1-50
33-34 wGA (n=136) 9 (8) 1-48
35 wGA (n=88) 7 (8) 1-59

676 infants 29-35 wGA hospitalized for community-acquired RSV disease were identified; hospital LOS data were available for 674 of the 676 infants. 322 of the 676 infants were admitted to the ICU; ICU LOS was available for 321 of these infants.

wGA=weeks gestational age; SD=standard deviation

Hospitalizations

In the 2014-2015 RSV season, RSV-confirmed hospitalizations were most frequent in infants <6 months of age1,2

Pie chart showing the percentage of RSV-confirmed hospitalizations for preterm infants and babies in two different age ranges

The percentage of RSV-confirmed hospitalizations that occurred in those who were <6 months of age was:

78% for the total group (n=702)

  • 75% for infants 29-32 wGA (n=237)
  • 79% for infants 33-34 wGA (n=283)
  • 80% for infants 35 wGA (n=182)
 

In the 2015-2016 RSV season, RSV-confirmed hospitalizations were most frequent in infants <6 months of age1,2

Pie chart showing the percentage of RSV-confirmed hospitalizations for preterm infants and babies in two different age ranges

The percentage of RSV-confirmed hospitalizations that occurred in those who were <6 months of age was:

78% for the total group (n=676)

  • 75% for infants 29-32 wGA (n=204)
  • 80% for infants 33-34 wGA (n=288)
  • 78% for infants 35 wGA (n=184)
 

ICU Admissions and Need for Mechanical Ventilation

In season 1, the 2014-2015 RSV season, RSV-confirmed ICU admission and need for invasive mechanical ventilation occurred more frequently in infants born at an earlier GA

Graph representing percentage of babies with RSV-confirmed ICU admission and need for mechanical ventilation by gestational age group (2014-2015)

Among the 29-32 wGA infants 49% were admitted to the ICU and 24% required invasive mechanical ventilation

Among the 702 infants identified during the 2014–2015 season, hospital LOS data were available for 678 infants; data pertaining to ICU admission status and need for IMV were available for 684 infants.

In season 1, the 2014-2015 RSV season, RSV-confirmed ICU admission occurred more frequently in infants born at an earlier GA and <3 months of age

Proportion of infants who required ICU admission

Chart showing RSV-confirmed hospitalization and ICU admission of babies by gestational and chronological age group (2014-2015)

Chronologic Age (CA)

68% of infants 29-32 wGA were admitted to the ICU when hospitalized at <3 months of age

In season 1, the 2014-2015 RSV season, the need for invasive mechanical ventilation occurred more frequently in infants <3 months of age

Proportion of infants who required invasive mechanical ventilation

Chart showing percentage of babies with RSV-confirmed need for invasive mechanical ventilation by gestational and chronological age group (2014-2015)

Chronologic Age (CA)

44% of infants 29-32 wGA required invasive mechanical ventilation when hospitalized at <3 months of age

During season 2, the 2015-2016 RSV season, ICU admission and need for mechanical ventilation were consistent across all GA groups

Graph representing percentage of babies with RSV-confirmed ICU admission and need for mechanical ventilation by gestational age (2015-2016)

Among the 29-32 wGA infants 48% were admitted to the ICU and 20% required invasive mechanical ventilation

During the 2015–2016 season, 678 infants were identified, hospital LOS data were available for 676 infants; for Season 2, data pertaining to ICU admission status were available for 678 infants, whereas data pertaining to need for IMV were available for 677 infants.

§Among the 288 33-34 wGA infants identified in 2015-2016, data pertaining to need for invasive mechanical ventilation were available for 287 infants.

During season 2, the 2015-2016 RSV season, ICU admission continued to occur more frequently in infants with younger chronologic age

Proportion of infants who required ICU admission

Chart showing percentage of babies with RSV-confirmed hospitalization and ICU admission by gestational and chronological age group (2015-2016)

Chronologic Age (CA)

70% of infants 29-32 wGA were admitted to the ICU when hospitalized at <3 months of age

During season 2, the 2015-2016 RSV season,the need for invasive mechanical ventilation continued to occur more frequently in infants with younger chronologic age

Proportion of infants who required invasive mechanical ventilation

Chart showing percentage of babies with RSV-confirmed need for invasive mechanical ventilation by gestational and chronological age group (2015-2016)

Chronologic Age (CA)

37% of infants 29-32 wGA required invasive mechanical ventilation when hospitalized at <3 months of age

Summary

SENTINEL1 conclusions are:

  • Earlier gestational age and younger CA were associated with higher risk of RSV hospitalization
  • Younger CA (<3 months) was associated with a higher risk of ICU admission and need for IMV, which was consistent in both seasons

Consistent trends seen in the 2014-2015 and 2015-2016 RSV seasons confirm that the risks of RSV–related hospitalizations remain and should be considered when identifying infants who are at high risk for severe RSV disease

References

  1. Anderson E, Krilov L, DeVincenzo J, et al. [poster #1279]. Presented at: ID Week, New Orleans, LA, October 26-30, 2016.
  2. Data on File, REF-10877, AstraZeneca Pharmaceuticals LP.