Table 1.

Characteristics of the study population included in the analysis

Study population	Studies (n)	Study characteristics
General population	29	n=30 169, age ranging from 12 to 95 years; 48% male
Patients with diabetes	18	n=9082, age ranging from 14 to 90 years; 43% male
Patients with hypertension	9	n=4123, age ranging from 19 to 90 years; 43% male
Patients with HIV	42	n=67 432, age ranging from 13 to 74 years; 36% male
Occupational group	2	n=153, age ranging from 22 to 59 years; one study only enrolled women and the other principally enrolled men
Family practice patients	7	n=3250, age ranging from 20 to 74 years; 44% male
Patients with lupus	1	n=43, age ranging from 16 to 55 years; 7% male
Rheumatoid arthritis	1	n=233, age ranging from 40 to 70 years; 17.2% male
Sickle cell anaemia	1	n=194, age ranging from 12 to 40 years; 43.3% male
Patients with chronic kidney disease	42	n=34 236, age ranging from 12 to 90 years; 58% male