Table 1.

Inclusion and exclusion criteria

Inclusion	Exclusion
Original observational studies or reports; primarily cross-sectional and cohort studies	If more than one article presenting results from the same study exist then only the most pertinent article was included.
Studies reporting results specifically for various age groups on people aged 60 and over	No reviews, experimental or clinical trials, or studies with subsample of the original study sample, unless it is still a representative sample and reports new relevant information
Representative of the general population (study samples from nursing homes, etc. are accepted)	No working populations
Reported separately some type of back pain (+ divided by region)	No native/aboriginal populations
Studies from developed countries only (e.g. countries with *advanced economies* according to IMF)	No traumatic related injuries
Any type of prevalence	No secondary back pain conditions (i.e. osteoporotic fractures)
Prevalence/incidence estimates specifically on people aged 60 and over	No indirect/weighted/adjusted prevalence estimates.
In studies with results from more than one period/survey, only the most recent year was included
At least theoretically possible that there were a minimum of 500 participants in each age group