Meta-analysis of the association between chronic periodontitis and chronic kidney disease

Table 2 Basic characteristics of clinical attachment level (mm) level difference between patients with chronic kidney disease and non-chronic kidney disease population

Ref.	Research location	Research type	Sample size (CKD/non-CKD)	Average CAL (mm, CKD/non-CKD)
Garcez et al[20]	United States of America	Cross-sectional study	80/80	0.54 ± 0.60/0.44 ± 0.56
Gavaldá et al[21]	Spain	Cross-sectional study	105/53	4.9 ± 2.1/4.2 ± 2.5
Frankenthal et al[22]	Israel	Cross-sectional study	35/35	4.43 ± 0.29/4.03 ± 0.25
Cengiz et al[23]	Türkiye	Cross-sectional study	68/41	3.1 ± 1.5/2.4 ± 1.4
Limeres et al[24]	Portugal	Cross-sectional study	44/44	1.04 ± 0.59/0.71 ± 0.55
Camacho-Alonso et al[25]	Spain	Cross-sectional study	91/118	1.77 ± 0.81/1.15 ± 0.41

CKD: Chronic kidney disease; CAL: Clinical attachment level.