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. 2020 Jun 4;2020(6):CD012431. doi: 10.1002/14651858.CD012431.pub2

Llor 2011a.

Study characteristics
Methods Clinical setting: primary healthcare centres
Single‐ or multicentre study: multicentre
Country of study: Spain
Unit of allocation: clusters
Inclusion criteria: patients aged 14 to 60 years diagnosed with acute pharyngitis with 1 or more Centor criteria (fever, sore throat, tonsillar exudate, tender cervical nodes, and/or absence of cough).
Exclusion criteria: patients with more than 5 episodes of pharyngitis over the last year; those with immunosuppressed condition, such as active neoplasm, AIDS, or reception of chemotherapy, radiotherapy, steroids, and/or immunosuppressive therapy; those with heart valve disease; rheumatic fever; an episode of pharyngitis treated with antibiotics in the previous 15 days; and those who had tonsillectomy.
Follow‐up: “evolution within the first month” (no more information reported).
Participants Number of clusters (n): 20 centres
Number of participants (n): 557 enrolled, 543 included in the analysis
Participant characteristics:

  1. age (distribution): mean age in years (SD) 31.7 (11.4);

  2. female participants (%): 62.8%;

  3. clinical severity distribution of Centor/McIsaac: Centor 1, 24.1%; Centor 2, 31.5%; Centor 3, 27.6%; Centor 4, 16.8%.
Interventions Management in intervention group(s): RADT alone (“Physicians allocated to the intervention group were provided with RADT”)
Type of RADT system used: enzyme immunoassay
Commercial name and brand of the RADT: OSOM Strep A test (Genzyme)
Management in control group(s): clinical grounds without a scoring system (“Those assigned to the control group managed streptococcal pharyngitis with only clinical criteria”)
Outcomes Primary outcome(s):

  1. percentage of antibiotic prescription;

  2. proportion of inappropriate antibiotic prescription (including both participants without GABHS infection treated with antibiotics and those with GABHS infection in which antibiotic therapy was not given).


Secondary outcome(s):

  1. type of antibiotics prescribed;

  2. validity of the RADT (sensitivity, specificity, predictive values);

  3. full clinical recovery at the third week (including participants without side effects, visits that required a change of treatment, or the presence of complications).
Notes Type of report: journal article
Source(s) of funding: funded by the Fondo de Investigaciones Sanitarias, the University and Innovation Department of Spain, and by the Catalan Society of Family Medicine. The Rapid Test Device OSOM StrepA of Genzyme was provided by Leti. All the trial authors declare they have received no honoraria from the Leti Laboratory for undertaking this study. Carl Llor declares having received tests free of charge from Leti for investigational studies. In the last 3 years Leti has covered the travel and accommodation costs for seeking the inclusion of physicians in a control group in the Happy Audit study in Murcia. Leti also covered the accommodation costs during an international congress on respiratory disease in primary care within the last year.
RCT registration number: ISRCTN23587778
We contacted the authors to confirm that physicians in the control group were not invited to prescribe antibiotics based on clinical criteria (although some of them might be aware of the Centor criteria).
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk "Participating primary healthcare centres were randomised to the intervention or to the control arm of the study, with an allocation ratio of 1:1, by a random sequence generated by a computer program."
Allocation concealment (selection bias) Unclear risk No description exists of any concealment of allocation.
Blinding of participants and personnel (performance bias)
All outcomes High risk Blinding is impossible in this context, and this lack of blinding is likely to influence the outcome.
Blinding of outcome assessment (detection bias)
All outcomes High risk Blinding is impossible in this context, and this lack of blinding is likely to influence the outcome.
Incomplete outcome data (attrition bias)
All outcomes Unclear risk Data were incomplete for 14 out of 557 participants without any explanation. Elsewhere, there is existence of incomplete outcome data, such as with regards to evolution of pharyngitis, and without explanation.
Selective reporting (reporting bias) High risk Missing data in outcome in the intervention group and in the control group (complete data for 274 out of 281 and 237 out of 262 participants, respectively).
Other bias Low risk None