Economic evaluations of neuraminidase inhibitors to control influenza

Review of the role of additional treatments including oseltamivir, oral steroids, macrolides, and vitamin supplementation for children with severe pneumonia in low- and middle-income countries

Background

Pneumonia is a major cause of death in children aged under five years. As children with severe pneumonia have the highest risk of morbidity and mortality, previous studies have evaluated the additional benefit of adjunctive treatments such as oseltamivir, oral steroids, macrolides, and vitamin supplementation that can be added to standard antibiotic management to improve clinical outcomes. The study reviewed the evidence for the role of these additional treatments for children with severe pneumonia in low- and middle-income countries (LMICs).

Methods

Four electronic databases were searched for English-language articles between 2000 to 2020. Systematic reviews (SRs) with meta-analyses, comparative cohort studies, and randomised controlled trials (RCTs) from LMICs that reported clinical outcomes for children with severe pneumonia aged between one month to 9 years who received adjunct treatment in addition to standard care were included. Risk of bias of included SRs was assessed using AMSTAR 2, and of individual studies using the Effective Public Health Practice Project (EPHPP) quality assessment tool for quantitative studies.

Results

Overall, the search identified 2147 articles, 32 of which were eligible, including 7 SRs and 25 RCTs. These studies evaluated zinc (4 SRs, 17 RCTs), Vitamin D (1 SR, 4 RCTs), Vitamin A (3 SRs, 1 RCT), Vitamin C (1 SR, 2 RCTs) and micronutrients (1 RCT). Most studies reported clinical outcomes of time to improvement, length of stay, and treatment failure (including mortality). No studies of oseltamivir, steroids, or macrolides fulfilling the inclusion criteria were identified. For zinc, pooled analyses from SRs showed no evidence of benefit. Similarly, a Cochrane review and one RCT found that Vitamin A did not improve clinical outcomes. For Vitamin D, an RCT evaluating a single high dose of 100 000 international units (IU) of vitamin D found a reduction in time to improvement, with 38%-40% documented vitamin D deficiency at baseline. However, two other studies of 1000 IU daily did not show any effect, but vitamin D status was not measured. For vitamin C, two studies found a reduction in time to symptom resolution in those with severe disease, with one reporting a shorter length of hospital stay. However, both studies were of weak quality. Most studies excluded malnourished children, and studies which included these children did not report specifically on the effect of micronutrients.

Conclusions

This review found that adjunctive zinc and vitamin A, in addition to standard care, does not improve clinical outcomes in children with severe pneumonia in LMICs (strong evidence). However, a reduction in time to symptom resolution was reported with high dose vitamin D supplementation in children with documented vitamin D deficiency (strong evidence from one study) and vitamin C (weak evidence), although further research is needed, especially in underweight children.

"If you have the flu symptoms, your asymptomatic spouse may better answer the willingness-to-pay question". Evidence from a double-bounded dichotomous choice model with heterogeneous anchoring

The small sample size of contingent valuation (CV) surveys conducted in patients may have limited the use of the single-bounded (SB) dichotomous choice format which is recommended in environmental economics. In this paper, we explore two ways to increase the statistical efficiency of the SB format: (1) by the inclusion of proxies in addition to patients; (2) by the addition of a follow-up dichotomous question, i.e. the double-bounded (DB) dichotomous choice format. We found that patients (n=223) and spouses (n=64) answering on behalf of the patient had on average a similar willingness-to-pay for earlier alleviation of flu symptoms. However, a patient was significantly more likely to anchor his/her answer on the first bid as compared to a spouse. Finally, our original DB model with shift effect and heterogeneous anchoring reconciled the discrepancies found in willingness-to-pay statistics between SB and DB models in keeping with increased statistical efficiency.

The impact of influenza on working days lost: a review of the literature

Seasonal influenza is a prevalent and highly contagious acute respiratory disease that, year on year, results in increased morbidity and mortality on a global scale. Because of the widespread and debilitating nature of the disease, annual influenza epidemics result in substantial workplace absenteeism, and the associated cost of lost productivity is a significant component of the substantial financial burden of the disease to society. The objective of this review was to identify studies that had attempted to quantify the impact of influenza upon otherwise healthy adults in terms of working days lost associated with an episode of influenza.Studies were included if they reported estimates of working days lost due to clinical, physician and/or self-diagnosis in adult patients or their dependants, or where this figure could be estimated from the data. Searches were conducted in MEDLINE, EMBASE, BIOSIS and the Cochrane Collaboration for articles published since 1995 in English, French or German. Of the 289 papers identified in the search, 28 (9.7%) met the inclusion criteria. The studies, involving study sites in North America, Western Europe, Asia and Australia, were categorized into three groups: (i) those reporting influenza diagnoses confirmed by laboratory testing, i.e. studies where influenza was the unambiguous cause of the working days lost (n = 7 studies reported in ten publications); (ii) those where influenza was confirmed by a physician without an accompanying laboratory test (n = 4 studies); and (iii) those where influenza was self-reported by study participants (n = 14 studies). Qualitative reporting of results was performed because of the large degree of heterogeneity observed between studies, potentially complicating the interpretation of any meta-analysis.The results from studies involving a laboratory-confirmed influenza diagnosis suggested that the mean number of working days lost ranged between 1.5 and 4.9 days per episode. Those papers that detailed working days lost per episode following physician diagnosis of influenza reported a range of 3.7-5.9 days per episode. Finally, estimates from papers reporting working days lost per episode of self-reported influenza ranged from <1 day to 4.3 days per episode.Influenza imposes a significant burden on society, and this review highlights the significant economic impact it causes, i.e. the loss of productivity caused by both absenteeism and by staff functioning at reduced capacity even after they have returned to work. A number of prophylaxis and treatment options exist for influenza and should be given serious consideration in an attempt to reduce the economic burden on society.

[Neuraminidase inhibitors in the general practice management of influenza: who prescribe them, when and with which results?]

OBJECTIVE

To describe in real-life conditions the flu therapeutic management, motivations to prescribe or not NAI (General Practitioners' (GPs) characteristics, decisional factors) and treated patients' course.

DESIGN

A prospective, longitudinal, pharmacoepidemiological study involved 305 GPs in France during 2002-2003 winter epidemic peak. All patients>or=1 year old, with a clinical diagnostic of flu were included.

RESULTS

One hundred and eighty-five GPs (150 NAI prescribing and 30 non-prescribing physicians) have included at least 1 patient. Prescribing physicians were the best informed on flu and NAI. 660 patients were analysed (250 NAI+ and 410 NAI-). 66% of NAI+ and 40% of NAI- attended to a consultation within 24 h (P<0.001). 31% of NAI+ and 20% of NAI- had a visit at home (P=0.002). Among the patients without complication at inclusion (N=585), 3% of NAI+ received an antibiotherapy vs 13% of NAI- (P<0.001). 43% of the patients had a sick leave, shorter for the NAI+ than NAI- (respectively, 3.7+/-1.7 vs 4.2+/-1.7 days, p=0.017). NAI was taken within 3 hours (median) after prescription by the 78% of the patients who returned their diary cards. The NAI+ patients had a faster improvement of symptoms than NAI- (within 24 h, respectively: 18 vs 5%, P<0.001) and they returned faster to routine activities (within 48 h, respectively: 27 vs 11%, P<0.001).

CONCLUSIONS

This study evidenced the good use of NAI by the physicians. It confirms their therapeutic efficacy in real-life conditions and suggests their prescription allows decreasing antibiotic co-prescriptions and sick leaves duration, profits to consider in NAI benefit/risk ratio.