Oseltamivir prophylaxis in controlling influenza outbreak in nursing homes: a comparison between three different approaches

Reducing unplanned hospital admissions from care homes: a systematic review

Background

Care homes predominantly care for older people with complex health and care needs, who are at high risk of unplanned hospital admissions. While often necessary, such admissions can be distressing and provide an opportunity cost as well as a financial cost.

Objectives

Our objective was to update a 2014 evidence review of interventions to reduce unplanned admissions of care home residents. We carried out a systematic review of interventions used in the UK and other high-income countries by synthesising evidence of effects of these interventions on hospital admissions; feasibility and acceptability; costs and value for money; and factors affecting applicability of international evidence to UK settings.

Data sources

We searched the following databases in December 2021 for studies published since 2014: Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews; Cumulative Index to Nursing and Allied Health Literature; Health Management Information Consortium; Medline; PsycINFO; Science and Social Sciences Citation Indexes; Social Care Online; and Social Service Abstracts. 'Grey' literature (January 2022) and citations were searched and reference lists were checked.

Methods

We included studies of any design reporting interventions delivered in care homes (with or without nursing) or hospitals to reduce unplanned hospital admissions. A taxonomy of interventions was developed from an initial scoping search. Outcomes of interest included measures of effect on unplanned admissions among care home residents; barriers/facilitators to implementation in a UK setting and acceptability to care home residents, their families and staff. Study selection, data extraction and risk of bias assessment were performed by two independent reviewers. We used published frameworks to extract data on intervention characteristics, implementation barriers/facilitators and applicability of international evidence. We performed a narrative synthesis grouped by intervention type and setting. Overall strength of evidence for admission reduction was assessed using a framework based on study design, study numbers and direction of effect.

Results

We included 124 publications/reports (30 from the UK). Integrated care and quality improvement programmes providing additional support to care homes (e.g. the English Care Homes Vanguard initiatives and hospital-based services in Australia) appeared to reduce unplanned admissions relative to usual care. Simpler training and staff development initiatives showed mixed results, as did interventions aimed at tackling specific problems (e.g. medication review). Advance care planning was key to the success of most quality improvement programmes but do-not-hospitalise orders were problematic. Qualitative research identified tensions affecting decision-making involving paramedics, care home staff and residents/family carers. The best way to reduce end-of-life admissions through access to palliative care was unclear in the face of inconsistent and generally low-quality evidence.

Conclusions

Effective implementation of interventions at various stages of residents' care pathways may reduce unplanned admissions. Most interventions are complex and require adaptation to local contexts. Work at the interface between health and social care is key to successful implementation.

Limitations

Much of the evidence identified was of low quality because of factors such as uncontrolled study designs and small sample size. Meta-analysis was not possible.

Future work

We identified a need for improved economic evidence and the evaluation of integrated care models of the type delivered by hospital-based teams. Researchers should carefully consider what is realistic in terms of study design and data collection given the current context of extreme pressure on care homes.

Study registration

This study is registered as PROSPERO database CRD42021289418.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (award number NIHR133884) and will be published in full in Health and Social Care Delivery Research; Vol. 11, No. 18. See the NIHR Journals Library website for further project information.

Effectiveness of Oseltamivir Prophylaxis in Influenza Outbreaks in Residential Aged Care

Influenza outbreaks in Aged Care Facilities (ACFs) can lead to hospitalizations and deaths. Influenza can spread rapidly through ACFs if precautionary measures are not taken. Along with influenza vaccination and precautionary hygiene measures, Oseltamivir Prophylaxis (OP) may be effective in reducing the attack rate of influenza by preventing new cases. A cohort study was carried out to investigate the effectiveness of OP use during influenza outbreaks in ACFs located within South Western Sydney Local Health District from 1 January 2015 to 31 December 2018. The main outcome assessed was the rate of OP failure (new cases of influenza in patients treated with OP) among ACF residents. Subgroups and various predictors of OP failure were investigated including presence of a dementia ward, high care ward, and days to Public Health Unit (PHU) notification. The cohort consisted of 86 ACF outbreaks involving 10,064 residents. OP prevented 90% of influenza cases during influenza outbreaks [0.1 RR (95% confidence interval (CI): 0.08–0.12); P < 0.0001]. ACFs with dementia wards had a 44% (0.56 relative risk (RR) (95% CI: 0.34–0.93); P < 0.05) lower OP failure rate. ACFs with high level care had an 87% (0.13 RR (95% CI: 0.05–0.38); P < 0.05) lower OP failure rate. OP is highly effective in preventing new cases of influenza during outbreaks in ACFs, especially in ACFs with dementia or high care wards. Mandatory reporting of influenza outbreaks to PHUs would ensure that ACFs are supported throughout the outbreak, which will facilitate reductions in hospitalizations and mortality.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenzaa

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Immunosenescence and Respiratory Infections Among Nursing Home Residents

Residents of nursing homes are at high risk of infectious complications due to respiratory infection. The nursing home setting places residents at high risk given the frequent contact among residents and by staff along with the possibility for continuous introduction of respiratory viruses from the community. Nursing home residents are among the most frail members of society. They have multiple comorbidities that can increase their risk of infection. Immunosenescence plays an important role in not only rendering these seniors susceptible in infection, particularly viral respiratory infection, but also interferes with protection. That is, the ability to mount a robust immune response to influenza and pneumococcal vaccine increase the risk. There have been a number of T cell deficits described in this population. CD4+ T cells, in particular T-regs and CMV-reactive CD4+ T cells, have been shown to be predictive of respiratory viral infection in this population. Although evidence exists that T cell subsets may correlate better with response to vaccine and protection, antibody responses to influenza vaccine remains an important correlate in this population. Large-scale epidemiologic studies are needed to establish better correlation between biomarkers for protection and respiratory and other pathogens that circulate in nursing homes.

Medications and Prescribing Patterns as Factors Associated with Hospitalizations from Long-Term Care Facilities: A Systematic Review

BACKGROUND

Residents of long-term care facilities (LTCFs) are at high risk of hospitalization. Medications are a potentially modifiable risk factor for hospitalizations.

OBJECTIVE

Our objective was to systematically review the association between medications or prescribing patterns and hospitalizations from LTCFs.

METHODS

We searched MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and International Pharmaceutical Abstracts (IPA) from inception to August 2017 for longitudinal studies reporting associations between medications or prescribing patterns and hospitalizations. Two independent investigators completed the study selection, data extraction and quality assessment using the Joanna Briggs Institute Critical Appraisal Tools.

RESULTS

Three randomized controlled trials (RCTs), 22 cohort studies, five case-control studies, one case-time-control study and one case-crossover study, investigating 13 different medication classes and two prescribing patterns were included. An RCT demonstrated that high-dose influenza vaccination reduced all-cause hospitalization compared with standard-dose vaccination (risk ratio [RR] 0.93; 95% confidence interval [CI] 0.88-0.98). Another RCT found no difference in hospitalization rates between oseltamivir as influenza treatment and oseltamivir as treatment plus prophylaxis (treatment = 4.7%, treatment and prophylaxis = 3.5%; p = 0.7). The third RCT found no difference between multivitamin/mineral supplementation and hospitalization (odds ratio [OR] 0.94; 95% CI 0.74-1.20) or emergency department visits (OR 1.05; 95% CI 0.76-1.47). Two cohort studies demonstrated influenza vaccination reduced hospitalization. Four studies suggested polypharmacy and potentially inappropriate medications (PIMs) increased all-cause hospitalization. However, associations between polypharmacy (two studies), PIMs (one study) and fall-related hospitalizations were inconsistent. Inconsistent associations were found between psychotropic medications with all-cause and cause-specific hospitalizations (11 studies). Warfarin, nonsteroidal anti-inflammatory drugs, pantoprazole and vinpocetine but not long-term acetylsalicylic acid (aspirin), statins, trimetazidine, digoxin or β-blockers were associated with all-cause or cause-specific hospitalizations in single studies of specific resident populations. Most cohort studies assessed prevalent rather than incident medication exposure, and no studies considered time-varying medication use.

CONCLUSION

High-quality evidence suggests influenza vaccination reduces hospitalization. Polypharmacy and PIMs are consistently associated with increased all-cause hospitalization.

The effect of timing of oseltamivir chemoprophylaxis in controlling influenza A H3N2 outbreaks in long-term care facilities in Manitoba, Canada, 2014-2015: a retrospective cohort study

Objective

This study examined the effect of the timing of administration of oseltamivir chemoprophylaxis for the control of influenza A H3N2 outbreaks among residents in long-term care facilities (LTCFs) in Manitoba, Canada, during the 2014–2015 influenza season.

Methods

A retrospective cohort study was conducted of all LTCF influenza A H3N2 outbreaks (n=94) using a hierarchical logistic regression analysis. The main independent variable was how many days passed between the start of the outbreak and commencement of oseltamivir chemoprophylaxis. The dependent variable was whether each person in the institution developed influenza-like illness (yes or no).

Results

Delay of oseltamivir chemoprophylaxis was associated with increased odds of infection in both univariate (t=5·41; df=51; P<·0001) and multivariable analyses (t=6·04; df=49; P<·0001) with an adjusted odds ratio of 1.3 (95% confidence interval [CI], 1·2–1·5) per day for influenza A H3N2.

Conclusions

The sooner chemoprophylaxis is initiated, the lower the odds of secondary infection with influenza in LTCFs during outbreaks caused by influenza A H3N2 in Manitoba. For every day that passed from the start of the outbreak to the initiation of oseltamivir, the odds of a resident at risk of infection in the facility developing symptomatic infection increased by 33%.

Comparison of the Biofire FilmArray Respiratory Panel, Seegene AnyplexII RV16, and Argene for the detection of respiratory viruses

BACKGROUND

Respiratory infections are common reasons for hospital admission, and are associated with enormous economic burden due to significant morbidity and mortality. The wide spectrum of microbial agents underlying the pathology renders the diagnosis of respiratory infections challenging. Molecular diagnostics offer an advantage to the current serological and culture-based methods in terms of sensitivity, coverage, hands-on time, and time to results.

OBJECTIVES

This study aimed to compare the clinical performance of three commercial kits for respiratory viral detection.

STUDY DESIGN

The performance of FilmArray Respiratory Panel, AnyplexII RV16, and Argene was compared using clinical respiratory samples (n = 224, comprising 189 nasopharyngeal swabs in Universal Transport Medium (UTM) and 35 endotracheal aspirates), based on common overlapping targets across the platforms. Influenza A "equivocal" and "no-subtype" samples by FilmArray were further compared to a laboratory-developed Influenza A/B test.

RESULTS AND CONCLUSIONS

The overall performance of all three platforms appeared to be comparable with regards to sensitivities (95.8-97.9%) and specificities (96.1-98.0%), detection of coinfections, and distinguishment of influenza from non-influenza cases. "Equivocal" and "no-subtype" samples by FilmArray mostly represented weak Influenza A by laboratory-developed test. Lower respiratory tract samples had comparable final-run success-rates and discordant-rates as compared to UTM. Coronavirus HKU1, which was not targeted by AnyplexII RV16, were detected as OC43. The expected test volume would be the main determinant for the selection of platform. Among the platforms, the FilmArray is the most automated but is of the lowest-throughput and has the highest reagent cost.

The Prophylactic Effect of Anti-influenza Agents for an Influenza Outbreak in a University Hospital

Objective From November 24 to December 9, 2013, an outbreak of the influenza (flu) A (H3) virus occurred in a tertiary-care university hospital (1,014 beds). We herein report the prophylactic effect of anti-flu agents for controlling the flu outbreak. Methods We administered pre- or post-exposure prophylaxis with anti-flu agents in flu outbreak. To test the effectiveness of prophylaxis in a flu outbreak, we used the posterior mean of the reproductive value during the pre- and post-intervention period. We also simulated the probability distribution of new flu cases. We performed an analysis to quantify the strength of the intervention effect. Results A total of 97 people were diagnosed with flu before the intervention, and 7 were diagnosed after the intervention. A molecular analysis of the flu virus revealed that this outbreak was due to the flu A (H3) virus. A total of 3,702 people received prophylaxis. There was a significant reduction in the reproductive value from 1.89 [95% confidence interval (CI), 1.59 to 2.24] to 0.65 (95% CI, 0.02 to 1.00) after the intervention (p<0.001). Conclusion Prophylaxis with anti-flu agents, along with prompt identification and isolation of infected individuals, was effective in reducing the impact of a flu outbreak in a hospital.

Evaluation of the use of oseltamivir prophylaxis in the control of influenza outbreaks in long-term care facilities in Alberta, Canada: a retrospective provincial database analysis

OBJECTIVES

To evaluate the impact of oseltamivir prophylaxis in the management and control of influenza outbreaks in long-term care facilities in Alberta, Canada.

SETTING AND PARTICIPANTS

Long-term care facilities where 127 influenza outbreaks were reported to public health authorities in Alberta, Canada, during two influenza seasons from 2013 to 2015.

DESIGN AND OUTCOME MEASURES

Using routinely collected surveillance and administrative data, we examined the association between decision-making time for oseltamivir recommendation as prophylaxis strategy for influenza outbreaks in long-term care facilities (explanatory variable) and the duration of an influenza outbreak, the postprophylaxis risk of influenza-like illness and hospitalisation among residents of long-term care facilities in Alberta (outcome variables) using multivariable linear and Poisson regression models.

RESULTS

Oseltamivir prophylaxis decision-making time was positively associated with the postintervention duration of an outbreak, with a 1-day delay in making decision on oseltamivir prophylaxis associated with 2.22 (95% CI 1.37 to 3.06) more days of the duration of an outbreak after controlling for potential confounding effect of the number of residents at risk at intervention, outbreak progression time, prevalence of influenza-like illness during outbreak progression, facility location, presence of mixed strain and based on optimal timing of oseltamivir prophylaxis. Although not statistically significant, a 1-day delay in making decision on oseltamivir prophylaxis was associated with a 5% (95% CI -1% to 11%) increase in the postintervention risk of influenza-like illness, and a 6% (95% CI -8% to 22%) increase in the postintervention risk of hospitalisation after controlling for the same potential confounders.

CONCLUSIONS

Our study demonstrated benefits of using oseltamivir prophylaxis to shorten the duration of influenza outbreaks; however, there were no significant differences in the influenza-like illness and hospitalisation risk occurring after the intervention. Surveillance data may offer means of rapid evaluation of oseltamivir prophylaxis in long-term care facilities as a public health measure.