Eleven observational studies were included (n=3,010). These included two prospective and nine retrospective studies. Ten studies were considered to be good quality and one was rated as fair. Follow-up ranged from one to four years. All of the included studies adjusted for confounding factors such as age, gender, comorbidities, medications and ejection fraction.
Chronic renal disease was associated with a statistically significant increase in all-cause mortality (HR 3.44, 95% CI 2.82 to 4.21; 11 studies, 12 comparisons). No significant heterogeneity was found.
Results were similar for the subgroup of patients with estimated glomerular filtration rate less than 60mL/min/1.73 m2 and for the sensitivity analyses.
The funnel plot suggested potential for publication bias, but was difficult to interpret due to the small number of studies.