Treating and preventing influenza in aged care facilities: a cluster randomised controlled trial.
BACKGROUND
Influenza is an important cause of morbidity and mortality for frail older people. Whilst the antiviral drug oseltamivir (a neuraminidase inhibitor) is approved for treatment and prophylaxis of influenza during outbreaks, there have been no trials comparing treatment only (T) versus treatment and prophylaxis (T&P) in Aged Care Facilities (ACFs). Our objective was to compare a policy of T versus T&P for influenza outbreaks in ACFs.


RESULTS
We performed a cluster randomised controlled trial in 16 ACFs, that followed a policy of either "T"-oseltamivir treatment (75 mg twice a day for 5 days)-or "T&P"-treatment and prophylaxis (75 mg once a day for 10 days) for influenza outbreaks over three years, in addition to enhanced surveillance. The primary outcome measure was the attack rate of influenza. Secondary outcomes measures were deaths, hospitalisation, pneumonia and adverse events. Laboratory testing was performed to identify the viral cause of influenza-like illness (ILI) outbreaks. The study period 30 June 2006 to 23 December 2008 included three southern hemisphere winters. During that time, influenza was confirmed as the cause of nine of the 23 ILI outbreaks that occurred amongst the 16 ACFs. The policy of T&P resulted in a significant reduction in the influenza attack rate amongst residents: 93/255 (36%) in residents in T facilities versus 91/397 (23%) in T&P facilities (p=0.002). We observed a non-significant reduction in staff: 46/216 (21%) in T facilities versus 47/350 (13%) in T&P facilities (p=0.5). There was a significant reduction in mean duration of outbreaks (T=24 days, T&P=11 days, p=0.04). Deaths, hospitalisations and pneumonia were non-significantly reduced in the T&P allocated facilities. Drug adverse events were common but tolerated.


CONCLUSIONS
Our trial lacked power but these results provide some support for a policy of "treatment and prophylaxis" with oseltamivir in controlling influenza outbreaks in ACFs.


BACKGROUND
[corrected] Australian Clinical Trials Registry ACTRN12606000278538.
National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The University of Sydney, Sydney, New South Wales, Australia.
Robert
R
Booy
Richard I
RI
Lindley
Dominic E
DE
Dwyer
Jiehui K
JK
Yin
Leon G
LG
Heron
Cameron R M
CR
Moffatt
Clayton K
CK
Chiu
Alexander E
AE
Rosewell
Anna S
AS
Dean
Timothy
T
Dobbins
David J
DJ
Philp
Zhanhai
Z
Gao
C Raina
CR
MacIntyre
D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001315:Australia / Q000453:epidemiology; D004196:Disease Outbreaks / Q000517:prevention & control / Q000706:statistics & numerical data; D004334:Drug Administration Schedule; D005260:Female; D006299:Health Services for the Aged / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007251:Influenza, Human / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control* / Q000821:virology; D008297:Male; D008954:Models, Biological; D053139:Oseltamivir / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D012111:Residence Characteristics / Q000706:statistics & numerical data
D000998:Antiviral Agents; D053139:Oseltamivir