Akmese 2014.

Methods	8‐week prospective RCT conducted in the Antenatal Care Unit of the Department of Obstetrics and Gynecology, Faculty of Medicine, Ege University, Turkey.
Participants	Inclusion criteria: Pregnant women (20 to 35 years; between 12 to 24 weeks' gestation; a physician diagnosis of LBP; no history of lumbar spine pathology prior to pregnancy; pain score of 4/10 or greater on VAS. Exclusion criteria: Heart disease; serious blood disease; diabetes; heart disease; chronic obstructive lung disease; multiple gestation; high risk pregnancy; previous abortion or curettage; not resident of Izmir (Turkey); no CD player, any hearing deficit.
Interventions	Intervention group (N = 37/33 analysed): PMR; 20‐minute session completed by each participant at home twice a day (morning and evening) for 8 weeks. At baseline, each participant attended a 2‐hour education session at the obstetrics department to check they understood and could complete the PMR exercises and breathing techniques. Each participant received handbook and a CD (prepared by Turkish Psychological Association). At 4‐weeks a follow‐up session took place at the obstetrics dept. to give feedback and check exercises. Control group (N = 36/33 analysed): participants instructed to lie down twice a day (morning and evening) for 20 minutes. At the end of the study participants received the same CD and handbook as the intervention group. Routine daily activity was not restricted for any group. Participants were asked to record their performance of the specified activities on a calendar in an attempt to encourage compliance. They were 'warned not to use any complementary treatment for LBP' during the study.
Outcomes	Primary outcome: pain (VAS 0 to 10), completed at baseline, weeks 4 and 8. Secondary outcome: Generic Health Status (Short Form‐36), completed at baseline, weeks 4 and 8. Personal information form (PIF), completed at baseline: demographics, pregnancy and obstetric history.
Condition (LBP, PP, LBPP)	LBP.
Notes	Financial support was provided by Ege University Scientific Research Project (No. 2007/ASYO/004). Note: on page 2, higher score for SF‐36 was attributed to deterioration, while the reverse is true, which was borne out in the results section, where improvement is illustrated with a higher score.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	'Random number table used to assign participants to control and experimental groups' but no further details on how the random number table was used.
Allocation concealment (selection bias)	Unclear risk	No information provided on allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Experimental group were aware of the benefit of exercise for their condition. Providers of training for PMR could not be blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	No assistance was given by staff to any participants completing assessment forms/questionnaires. At the end of the study (week 8) the study co‐ordinator, who was blinded to group and timing of assessment, collected all assessment forms.
Incomplete outcome data (attrition bias) effect of intervention	Low risk	There was a 8% drop‐out rate from each group that were not accounted for in the analysis, nor were reasons provided for drop‐out.
Selective reporting (reporting bias)	Low risk	Means and SD were provided for primary and secondary outcomes at each time point (weeks 4 and 8) for all participants completing the study, N = 33 in experimental and N = 33 in control group.
Other bias	Low risk	VAS scores were similar between groups at baseline, however SF‐36 scores were not similar at baseline. Sample size very small, however there were very specific inclusion criteria and the authors controlled for use of co‐interventions in both groups and participants reported similar adherence to program.