Association between periodontal disease and mortality in people with CKD: a meta-analysis of cohort studies

BMC Nephrology

Table 3 Subgroup analyses for the effects of periodontal disease on all-cause mortality in people with CKD

Overall and subgroup analysis	No. of studies	Heterogeneity		Model	Meta-analysis			P value between subgroups
Overall and subgroup analysis	No. of studies	P	I² (%)	Model	RR	95% CI	P
Overall	8	0.041	52.2	Random-effect	1.254	1.046–1.503	0.015
CKD stage								0.79
CKD stage 3–5	3	0.75	0.0%	Fix-effect	1.245	1.119–1.385	0.000
CKD stage 5D (hemodialysis)	4	0.030	66.4%	Random-effect	1.315	0.885–1.954	0.176
Transplant	1	NA	NA	NA	7.17	1.4–76.4	NA
Adjustment for confounding factors
Unadjusted	1	NA	NA	NA	7.17	1.4–76.4	NA
Adjusted	7	0.072	48.2%	Fixed-effect	1.194	1.091–1.306	0.016	0.77
Adjusted for smoking and other variables	6	0.058	53.3%	Random-effect	1.209	1.016–1.438	0.032
Adjusted for diabetes and other variables	6	0.093	47.1%	Fixed-effect	1.175	1.071–1.288	0.001
Adjusted for diabetes, hypertension and other variables	4	0.664	0.0%	Fixed-effect	1.264	1.137–1.404	0.000
Study duration								0.14
Short (< 5 years)	3	0.029	71.9%	Random-effect	1.116	0.855–1.457	0.418
Long (≥ 5 years)	5	0.448	0.0%	Fixed-effect	1.429	1.173–1.742	0.000
Diagnostic criteria for periodontal disease								0.23
PPD, CALs	5	0.838	0%	Fixed-effect	1.422	1.171–1.727	0.000
CPITN	3	0.009	78.8%	Random-effect	1.125	0.812–1.559	0.478
Regions								0.99
Asian countries	2	0.227	31.6%	Fixed-effect	1.257	1.123–1.407	0.000
European countries and USA	6	0.045	55.8%	Random-effect	1.259	0.927–1.710	0.14
Reference population								0.66
Healthy	4	0.752	0.0%	Fixed-effect	1.253	1.128–1.393	0.000
Healthy to mild periodontal disease	4	0.012	72.4%	Random-effect	1.410	0.844–2.356	0.189

Abbreviations: RR relative risk, CI confidence interval, PPD pocket probing depth, CALs clinical attachment levels, CPITN Community Periodontal Index of Treatment Needs Index, NA data not available

ISSN: 1471-2369