ANZCTR	Australian New Zealand Clinical Trials Registry
BA	Behavioural Activation
BPI	Brief Pain Inventory
CENTRAL	Cochrane Central Register of Controlled Trials
CI	Confidence Interval
CINAHL	Cumulative Index to Nursing and Allied Health Literature
COBRA	Cost and Outcome of Behavioural Activation versus Cognitive Behavioural Therapy for Depression
GRADE	Grading of Recommendations Assessment, Development, and Evaluation
GRADEpro GDT	GRADEpro Guideline Development Tool
ISRCTN	International Standard Randomised Controlled Trial Number
MeSH	Medical Subject Headings
MD	Mean Difference
NRS	Numeric Rating Scale
PICOS	Population, Intervention, Comparator, Outcome, and Study design
PRESS	Peer Review of Electronic Search Strategies
PRISMA	Preferred Reporting Items for Systematic Reviews and Meta-Analyses
PRISMA-P	Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols
PROSPERO	International Prospective Register of Systematic Reviews
RCT	Randomised Controlled Trial
RoB 2	Cochrane Risk of Bias 2 tool
SMD	Standardised Mean Difference
SWiM	Synthesis Without Meta-analysis
VAS	Visual Analogue Scale
WHO ICTRP	World Health Organization International Clinical Trials Registry Platform