Clark 2007.

Methods	Randomised controlled trial
Participants	808 female patients over the age of 18, with physician‐diagnosed asthma in the University of Michigan Health System, United States of America, were randomly assigned to 2 groups. Some of them came from speciality clinics. Patients had to have had active symptoms in the past 12 months and had been enrolled in one of the participating asthma related clinics. They were also required to have no extenuating medical or mental conditions and access to telephone. 424 women were randomised to the intervention group and 384 to the control group.
Interventions	Standard asthma education which does not emphasise sex and gender issues was provided at the time of the clinic visit. The intervention was a behavioural education programme delivered by a nurse health educator through telephone counselling. Based on social cognitive theory, women were introduced to a problem‐solving process to undertake in association with their asthma management plan. At baseline the patient's level of self‐management was determined and then telephone counselling was tailored to that level. Sex and gender‐role related asthma problems were assessed and women were encouraged to keep a diary with a Peak Expiratory Flow Meter to monitor their condition. Six educational telephone calls were made over the 12‐month study period to the intervention women. Control: The usual care group received treatment based on National Asthma Education Prevention Program guidelines as well as telephone follow up for the purposes of monitoring only
Outcomes	1. Frequencies of daytime and night‐time asthma symptoms 2. Days and nights that the woman had missed work or study 3. Self‐reported emergency department visits, hospitalisations, unscheduled urgent visits to a clinic and scheduled clinic visits in the 12 months before the study (i.e. at baseline) and at study follow up, were recorded 4. Medical record data for asthma emergency department visits and hospitalisation from a Data Warehouse during the corresponding time periods 5. Sex and gender role‐related queries were made relating to symptoms and the menstrual cycle, pre‐menstrual syndrome, contraceptive pill, hormone replacement therapy and urinary incontinence. Asthma problems relating to housework, washing or cleaning products, fragrances, cosmetics and hair products, exposures through child care and symptoms associated with social and sexual activity. 6. The Juniper's Mini Asthma Quality of Life Questionnaire was used to measure a woman's quality of life 7. A scale of self‐confidence for asthma management 8. The Zimmerman Scale was used to assess the level of a woman's self‐regulation ability
Notes	The authors acknowledge that more women with persistent asthma were assigned to the treatment group (P = 0.003) The impact of this is difficult to anticipate: as the women in the intervention group were sicker, it may have limited the impact of the intervention. Conversely, the intervention may have been perceived as more effective as the women had greater scope for improvement. The major potentially confounding variable of smoking was not assessed in this study; data on smoking rates were not collected. Medical record data were collected for the corresponding time periods and compared with self reports ‐ data triangulation
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“randomisation processes were based on random length permuted blocks”
Allocation concealment (selection bias)	Unclear risk	Insufficient information
Blinding (performance bias and detection bias) All outcomes	Low risk	“Participants' physicians were blind to the assignment of their patients in this study” “Data collectors were blind to the assignment of the women to the study arms” It would not have been possible to blind the women from the group allocation
Incomplete outcome data (attrition bias) All outcomes	Low risk	“There were no differences in dropouts due to demographic variables, disease severity and important outcomes between the two groups.”
Selective reporting (reporting bias)	Low risk	All of the study’s pre‐specified outcomes are reported
Other bias	High risk	“It happened that more women with persistent asthma were assigned to the treatment group. As noted this fact could have made intervention results more difficult to achieve given that the women were sicker conversely it could have provided more room for women to improve.” Smoking rates were not assessed