The impact of targeting all elderly persons in England and Wales for yearly influenza vaccination: excess mortality due to pneumonia or influenza and time trend study

Abstract

ObjectiveTo investigate the impact on mortality due to pneumonia or influenza of the change from risk-based to age group-based targeting of the elderly for yearly influenza vaccination in England and Wales.DesignExcess mortality estimated using time series of deaths registered to pneumonia or influenza, accounting for seasonality, trend and artefacts. Non-excess mortality plotted as proxy for long-term trend in mortality.SettingEngland and Wales.ParticipantsPersons aged 65–74 and 75+ years whose deaths were registered to underlying pneumonia or influenza between 1975/1976 and 2004/2005.Outcome measuresMultiplicative effect on average excess pneumonia and influenza deaths each winter in the 4–6 winters since age group-based targeting of vaccination was introduced (in persons aged 75+ years from 1998/1999; in persons aged 65+ years from 2000/2001), estimated using multivariable regression adjusted for temperature, antigenic drift and vaccine mismatch, and stratified by dominant circulating influenza subtype. Trend in baseline weekly pneumonia and influenza death rates.ResultsThere is a suggestion of lower average excess mortality in the six winters after age group-based targeting began compared to before, but the CI for the 65–74 years age group includes no difference. Trend in baseline pneumonia and influenza mortality shows an apparent downward turning point around 2000 for the 65–74 years age group and from the mid-1990s in the 75+ years age group.ConclusionsThere is weakly supportive evidence that the marked increases in vaccine coverage accompanying the switch from risk-based to age group-based targeting of the elderly for yearly influenza vaccination in England and Wales were associated with lower levels of pneumonia and influenza mortality in older people in the first 6 years after age group-based targeting began. The possible impact of these policy changes is observed as weak evidence for lower average excess mortality as well as a turning point in baseline mortality coincident with the changes.

Modelling the population effectiveness of the national seasonal influenza vaccination programme in Scotland: The impact of targeting all individuals aged 65 years and over

“…There are few studies in the UK that have focused on the vaccination programme among those aged 65+ years. In contrast to our results for Scotland, Mann et al found weak evidence of a reduction in influenza and pneumonia‐related mortality in England and Wales following the mid‐2000 policy change. However, their approach uses a longer definition of the flu year (week 26 to week 25), therefore incorporating deaths that occur outside the flu season.…”

“…Studies in the USA and Italy found no evidence of a reduction in all‐cause mortality among the over 65s, while a study in Holland did find evidence of a reduction . The failure to find evidence in the USA and Italian studies may be due to a limited period with sufficiently high vaccine coverage . There are few studies in the UK that have focused on the vaccination programme among those aged 65+ years.…”

“…For each outcome of interest, we calculate the number of excess observations (defined as observed count minus expected count) for each flu season (week 46‐week 9). To quantify the change in policy's impact on excess deaths/hospitalisations, we follow the work of Mann et al and fit a Gaussian regression model to these data. For the ST model, we use a model that contains a dummy variable that takes the value 0 for 1981‐mid‐2000 and 1 for mid‐2000‐2012 to capture the mid‐2000 change in vaccination policy.…”

“…While there is evidence to suggest that the influenza vaccine is effective at preventing influenza illness and its complications, the population effectiveness of the UK vaccination programme is not fully understood. While previous modelling work in England suggests that the vaccination programme, which targets clinical risk groups as well as individuals aged 65+ years, is cost‐effective and associated with a reduction in the incidence of laboratory confirmed influenza illness as well as reduced levels of pneumonia and influenza‐related mortality, the same knowledge does not exist for Scotland. Understanding how many deaths/hospitalisations have been prevented among the over 65s is an important first step in this direction.…”

Androgen deprivation therapy for prostate cancer and the risk of hospitalisation for community-acquired pneumonia

“…All models were adjusted for the following potential confounders measured at cohort entry: age, year of cohort entry, body mass index (BMI), smoking status, alcohol-related disorders, pre-diagnostic prostate-specific antigen (PSA) levels (closest measurement before cohort entry) and seasonality (with high-risk season defined as 1 October to 31 March) 25 26. The models also included previous cancer diagnoses (excluding non-melanoma skin cancers), COPD, asthma, bronchitis and bronchiectasis, in the year before cohort entry.…”