Regardless of the diagnosis code slots queried on each claim, rates of hospitalization with diagnoses of dialysis access infection, including peritonitis — which overwhelmingly occurs among patients on peritoneal dialysis — have been decreasing, although interpretation of these data without consideration of concurrent data regarding bacteremia and septicemia is a clear mistake. In fact, the increases in the admission rates for bacteremia and septicemia during the study era among both incident and prevalent dialysis patients are slightly larger in absolute magnitude than the concurrent decreases in the admission rates for dialysis access infections. Thus, even if a substantial minority of the hospitalized cases of septicemia were originally due to infections of sites other than the vascular access, it would be true that the incidence of hospitalization for either simple or complicated infection of the access did not change during the study era. As we described previously, moreover, these data only summarize the incidence of access infections of sufficient severity to necessitate hospitalization. They do not speak to the incidence of access infections in any setting; the incidence of hospitalized access infections could decrease even if the incidence of all access infections were to be stable, in the case that access infections diagnosed in the outpatient setting were promptly and effectively treated.
Regional estimates indicate that, among both incident and prevalent dialysis patients, the East North Central and South Atlantic divisions have the highest admission rates in the country. This is an interesting finding, as the percentage of black patients is generally high in both of these areas. Dialysis providers may consider quality improvement efforts targeted at vascular access care among black patients.
The seasonality of hospitalization for dialysis access infections is vivid, but the timing of peaks and nadirs during the annual cycle is different than for many other pathologies, including cardiovascular events. In the case of access infections, the rate of hospitalization peaks during summer months and reaches its annual nadir during the winter. Potential explanations include the impact of skin perspiration on bacterial growth, as well as bacterial growth in pools, lakes (including lakes used for drinking water), and private wells. There have been no detailed studies about the seasonal pattern of access infections.