Interventions for the interruption or reduction of the spread of respiratory viruses

BACKGROUND

Viral epidemics or pandemics such as of influenza or severe acute respiratory syndrome (SARS) pose a significant threat. Antiviral drugs and vaccination may not be adequate to prevent catastrophe in such an event.

OBJECTIVES

To systematically review the evidence of effectiveness of interventions to interrupt or reduce the spread of respiratory viruses (excluding vaccines and antiviral drugs, which have been previously reviewed).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 4); MEDLINE (1966 to November 2006); OLDMEDLINE (1950 to 1965); EMBASE (1990 to November 2006); and CINAHL (1982 to November 2006).

SELECTION CRITERIA

We scanned 2300 titles, excluded 2162 and retrieved the full papers of 138 trials, including 49 papers of 51 studies. The quality of three randomised controlled trials (RCTs) was poor; as were most cluster RCTs. The observational studies were of mixed quality. We were only able to meta-analyse case-control data. We searched for any interventions to prevent viral transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection and hygiene). Study design included RCTs, cohort studies, case-control studies, cross-over studies, before-after, and time series studies.

DATA COLLECTION AND ANALYSIS

We scanned the titles, abstracts and full text articles using a standardised form to assess eligibility. RCTs were assessed according to randomisation method, allocation generation, concealment, blinding, and follow up. Non-RCTs were assessed for the presence of potential confounders and classified as low, medium, and high risk of bias.

MAIN RESULTS

The highest quality cluster RCTs suggest respiratory virus spread can be prevented by hygienic measures around younger children. Additional benefit from reduced transmission from children to other household members is broadly supported in results of other study designs, where the potential for confounding is greater. The six case-control studies suggested that implementing barriers to transmission, isolation, and hygienic measures are effective at containing respiratory virus epidemics. We found limited evidence that the more uncomfortable and expensive N95 masks were superior to simple surgical masks. The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions about these measures.

AUTHORS' CONCLUSIONS

Many simple and probably low-cost interventions would be useful for reducing the transmission of epidemic respiratory viruses. Routine long-term implementation of some of the measures assessed might be difficult without the threat of a looming epidemic.

Delayed antibiotics for respiratory infections

BACKGROUND

Modest benefits of antibiotics for acute upper respiratory tract infections have to be weighed against common adverse reactions, cost and antibacterial resistance. There has been interest in ways to reduce antibiotic prescribing. One strategy is to provide the prescription, but advise delay of more than 48 hours before use, in the hope symptoms resolve first. Advocates suggest this will preserve patient satisfaction. This review asks what effect delayed antibiotics have on clinical outcomes of respiratory infections, antibiotic use and patient satisfaction.

OBJECTIVES

To evaluate the prescribing strategy of delayed antibiotics for acute respiratory tract infections compared to immediate or no antibiotics for clinical outcomes, antibiotic use and patient satisfaction.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2006); MEDLINE (January 1966 to January Week 2, 2007), EMBASE (1990 to Week 2, 2007) and Current Contents - ISI Web of Knowledge (1998 to January 2007).

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving patients of all ages defined as having an acute respiratory infection were included in which delayed antibiotics were compared to antibiotics used immediately or no antibiotics. Outcomes measured included clinical outcomes, antibiotic use and patient satisfaction.

DATA COLLECTION AND ANALYSIS

Data were collected and analysed by three review authors.

MAIN RESULTS

Nine trials were eligible on the basis of design and relevant outcomes. For most clinical outcomes there was no difference between delayed, immediate and no antibiotics. Antibiotics prescribed immediately were more effective than delayed for fever, pain and malaise in some studies of patients with acute otitis media and sore throat but for other studies there was no difference. There was no difference for the common cold and bronchitis. Delaying antibiotic prescriptions reduced antibiotic use, and in three studies, reduced patient satisfaction compared to immediate antibiotics. In the other two studies comparing delayed and immediate antibiotics measuring satisfaction, there was no difference. Two studies also included a 'no antibiotics' arm for bronchitis and sore throat: there was no difference in symptom resolution nor patient satisfaction from antibiotic delay. In one study, but not the other, antibiotic use was significantly decreased with no, rather than delayed, antibiotics.

AUTHORS' CONCLUSIONS

For most clinical outcomes there is no difference between the strategies. Immediate antibiotics was the strategy most likely to provide the best clinical outcomes in patients with sore throat and otitis media. Delaying or avoiding antibiotics, rather than providing them immediately, reduces antibiotic use for acute respiratory infections. Delay also reduced patient satisfaction in three trials, compared to immediate antibiotics with no difference in two other trials. Delaying antibiotics seems to have little advantage over avoiding them altogether where it is safe to do so.

Topical analgesia for acute otitis media

BACKGROUND

Acute otitis media (AOM) is a spontaneously remitting disease for which pain is the most distressing symptom. Antibiotics are now known to have less benefit than previously assumed.

OBJECTIVES

To assess the effectiveness of topical analgesia for AOM.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2006), MEDLINE (1966 to May Week 3 2006), EMBASE (1990 to December 2005) and LILACS (1982 to September 2005) without language restriction, and the reference lists of articles. We also contacted manufacturers and authors.

SELECTION CRITERIA

Double-blind randomised or quasi-randomised controlled trials comparing an otic preparation with an analgesic effect (excluding antibiotics) versus placebo or an otic preparation with an analgesic effect (excluding antibiotics) versus any other otic preparation with an analgesic effect, in adults or children presenting at primary care settings with AOM without perforation.

DATA COLLECTION AND ANALYSIS

Potential studies were screened independently and trial quality was assessed by three authors, and differences were resolved by discussion. Data was then independently extracted from the trials selected by two authors. We contacted the authors of three trials to acquire additional information not available in published articles.

MAIN RESULTS

Our searches yielded 356 records; four trials met our criteria. One trial with 54 participants compared treatment with anaesthetic ear drops versus an olive oil placebo immediately at diagnosis. All patients were also given paracetamol. There was a statistically significant pain reduction of 25% in those receiving anaesthetic drops 30 minutes after instillation. Three trials (with one common co-author) compared anaesthetic ear drops with naturopathic herbal ear drops in 274 patients. One of these trials also used antibiotics in both groups. There were statistically significant differences at instillation of drops, or 15 or 30 minutes after the instillation (or both) on one to three days after diagnosis, always favouring the naturopathic group in each trial.

AUTHORS' CONCLUSIONS

The evidence from these four randomised controlled trials, only one of which addresses the most relevant question of primary effectiveness, is insufficient to know whether ear drops are effective or not.

Delayed antibiotics for symptoms and complications of respiratory infections

BACKGROUND

The use of antibiotics for upper respiratory tract infections is controversial. Any benefits have to be weighed against common adverse reactions (including rash, abdominal pain, diarrhoea and vomiting), cost and antibacterial resistance. There has been interest in ways to reduce antibiotic prescribing for acute respiratory infections. One is delaying the use of prescribed antibiotics by more than 48 hours for acute upper respiratory tract infections. Such methods have been shown to reduce prescribing. This review asks what effect this practice has on the clinical course of the illness.

OBJECTIVES

To evaluate the clinical effect of delayed antibiotic use in acute upper respiratory tract infections compared to immediate use of antibiotics

SEARCH STRATEGY

The following electronic databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2004) which includes the Acute Respiratory Infection Groups' specialised register; MEDLINE (January 1966 to January Week 1 2004), EMBASE (1990 to September 2003) and Current Contents (1998 to 2003). The search was carried out by an expert librarian. Abstracts of identified articles were used to determine which studies were trials.

SELECTION CRITERIA

Randomised controlled trials involving patients of all ages defined as having acute otitis media, acute pharyngitis, sore throat, common cold, a viral upper respiratory tract infection, acute sinusitis, and acute bronchitis were included in which delayed antibiotics are compared to antibiotics used immediately. Delayed antibiotic use was defined as the use of or advice to use antibiotics more than 48 hours after the initial consultation. 'Immediate antibiotic use' was defined as the immediate use of oral antibiotics given at the initial consultation. Clinical outcomes measured included: the presence or absence of fever, cough, pain, duration and severity of illness, complications of the disease, adverse effects from the antibiotics. Trial quality was assessed independently by two reviewers who were blinded to the author, journal and results of each study.

DATA COLLECTION AND ANALYSIS

Data was collected by two reviewers who were blinded to the author and journal. Data were analysed and reported using RevMan.

MAIN RESULTS

Seven trials were eligible on the basis of design and all reported patient-centred outcomes. Methodological quality of included trials was generally high. There was no difference between immediate and delayed antibiotic groups for symptoms on day one and day seven. For most symptom measures there was no significant difference between the immediate and delayed antibiotic groups. Missing data and marked heterogeneity between study outcomes prevented pooling of results as a meta-analysis. Three studies out of six reporting fever, all involving patients with sore throat, indicated that there was more fever in the delayed antibiotic group. The remaining three studies showed no difference. There was no significant symptom difference for patients with cough or the common cold between the two intervention groups. Pain and malaise severity scores at day three significantly favoured the immediate antibiotic group in children with acute otitis media (Little 2001). In this study by Little 2001 of children with otitis media proxies for other malaise related outcomes were reported, including 'last day of crying' which favoured the immediate antibiotic group by approximately 16 hours (0.69 days; 95% CI 0.31 to 1.07). In the same study, just over half a spoon of paracetamol a day less was used in the immediate antibiotic group (0.59; 95% CI 0.25 to 0.93). There was no significant difference between the intervention groups for the adverse outcome of rash. Two studies reported the outcome of vomiting which was reduced in the immediate antibiotic group in children with suspected streptococcal pharyngitis in El-Daher 1991 but there was no difference in children with sore throat in Little 1997. Diarrhoea was reported by three studies of which two showed no difference Little 1997; Arroll 2002a while Little 2001 reported less diarrhoea in the delayed antibiotic group in children with otitis media.

REVIEWERS' CONCLUSIONS

When considering treatment options for upper respiratory tract infections, the option of delayed antibiotics has been used in an attempt to reduce the use of antibiotic prescriptions. This review shows that for all symptom scores the evidence varies between trials. Most symptom outcomes show no difference between immediate and delayed antibiotic groups. Three of the six studies, all involving patients with sore throat, indicated that patients in the delayed antibiotic group had significantly more fever that their counterparts in the immediate antibiotic group. The other three showed no difference for the outcome of fever. There is evidence indicating that for children with otitis media, pain and malaise scores are worse in the delayed antibiotic group compared to the immediate antibiotic group. This price must be weighed up against the benefits of reduced antibiotic prescribing. Future randomised controlled trials of delaying antibiotics as an intervention should fully report symptoms as well as changes of prescription rates.