Table 1.

Characteristics of included primary prevalence study reports (n=488) providing data for the period 1987–2017

Variables	N (%)*
Study type
Peer-reviewed	194 (40)
Report or survey	294 (60)
Region (Global Burden of Disease super regions)
Central Europe, Eastern Europe and Central Asia	75 (15)
High Income	300 (61)
Latin America and Caribbean	27 (6)
North Africa and Middle East	20 (4)
South Asia	9 (2)
Southeast Asia, East Asia and Oceania	25 (5)
Sub-Saharan Africa	32 (7)
Prevalence
Any prevalence period	484 (99)
Unclear prevalence period	4 (1)
Point prevalence	57 (12)
Incidence	9 (2)
Age groups
0–4	28 (6)
5–9	33 (7)
10–14	214 (44)
15–19	385 (79)
20–24	256 (52)
25–29	264 (54)
30–34	270 (55)
35–39	273 (56)
40–44	281 (58)
45–49	287 (59)
50–54	297 (61)
55–59	294 (60)
60–64	286 (59)
65–69	276 (57)
70–74	268 (55)
75–79	257 (53)
80–84	245 (50)
85–89	243 (50)
90–94	241 (49)
95+	240 (49)
Data for both genders available	472 (97)
Representative sample	446 (91)
Acceptable low back pain definition	79 (16)

*Numbers do not add up to the total number of reports (488) because some reports measured more than one prevalence period.