BMP	Barometric pressure
CGRP	Calcitonin gene-related peptide
CI	Confidence interval
CO	Carbon monoxide
ED	Emergency department
EPA	Environmental pain approach
EPOSA	European Project on Osteoarthritis
LBP	Low-back pain
LIC	Low-income countries
NO	Nitric oxide
NO2	Nitrogen dioxide
NOx	Nitric oxides
O3	Ozone
OA	Osteoarthritis
OR	Odds ratio
PM	Particulate matter
PR	Prevalence ratios
PROs	Patient-reported outcomes
QoL	Quality of Life
RA	Rheumatoid arthritis
RR	Relative risk
SD	Standard deviation
TRP	Transient receptor potential
TTH	Tension-type headache