Chatkin 2006.

Methods	Prospective, multicentre, randomised controlled trial
Participants	Aged at least 12 with moderate or severe persistent asthma, according to Global Initiative for Asthma (GINA) in Porto Alegre, Brazil; 271 patients were randomised into 2 groups. The participants were put forward by physicians from all over the country (it does not state whether primary or secondary care physicians) for the trial, in this way there were patients from 15 states of the country.
Interventions	Both groups received three packages of salmeterol/fluticasone for 3 months supplied by a drug company and routine care from their own physician. The participants in the intervention group received a phone call once every 2 weeks to promote treatment adherence. Control: The control group received initial and final telephone calls for collection of demographic information only
Outcomes	1. Adherence ‐ percentage of participants taking 85% or more of the prescribed doses of salmeterol/fluticasone. Adherence was measured according to the number of inhalations that were recorded on the disks. This was obtained from the disks that were returned to the office. They excluded patients who did not return the devices. 2. The difference in adherence between the control and telephone intervention groups
Notes	All participants entered into the study were required to have a residential telephone number not only a mobile, this may have been a source of bias. In addition, exclusion criteria were: mild persistent asthma, pregnancy or breast feeding, intention to move during the course of the study, regular use or recent past abuse of alcohol or illicit drugs and clinically significant active general medical condition; 4 patients were excluded due to these criteria. Little information was given in the study report regarding randomisation and blinding.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information
Allocation concealment (selection bias)	Unclear risk	Insufficient information
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Insufficient information
Incomplete outcome data (attrition bias) All outcomes	High risk	10 patients were not included because they did not return their drug disks and 8 for not responding to the telephone calls
Selective reporting (reporting bias)	Low risk	No evidence of selective reporting
Other bias	High risk	Drugs were supplied for free to the intervention group by a drugs company as oppose to the real‐world situation where patients would have to pay the high cost of their inhaler drugs themselves. Also patients adhere more when they know they are being monitored, however, this cannot be controlled for.