2009 ADR v2 Atlas of ESRD - United States Renal Data System

5
App A
pg 378
The number of cardiovascular conditions (congestive heart failure,
atherosclerotic heart disease, other cardiac disease, cerebrovascular
disease, peripheral vascular disease), along with data on
diabetes as primary cause of renal failure, COPD, and hemoglobin
and serum albumin values, are obtained from the ME form.
Employment status is obtained from question 73 of the Patient
Questionnaire: “Are you now working for pay (receiving taxable
wages)? If yes, full-time or part-time?”
Information on the kind of work employed patients were doing
is obtained from question 74 of the Patient Questionnaire: “If yes
(now working for pay), what kind of work are you doing now?” Jobs
were classified into occupational status categories 1 (high) to 7 (low)
using the Hollingshead occupational status scale.
Data on patient-reported ability to work is obtained from question
72 of the Patient Questionnaire: “Are you now able to work
for pay?”
Data on receipt of disability income is obtained from question 75
of the Patient Questionnaire: “Are you receiving disability benefits
(SSDI, SSI) from Social Security?”
The Adjusted Activity Score is obtained from responses to the
94-item Human Activity Profile, reproduced for use in the CDS with
permission of the author. The Adjusted Activity Score is defined as a
measure of usual daily activities, and is interpreted as providing the
best estimate of an individual’s average level of energy expenditure.
PHYSICAL ACTIVITY & LABORATORY MARKERS OF
NUTRITION & INFLAMMATION AMONG CDS PARTICIPANTS
Participants in the CDS were asked about physical activity using the
94-item Human Activity Profile (HAP), which has been previously
shown to correlate with physical activity measured by accelerometry
and with physical performance among patients with end-stage renal
disease (Johansen et al.). The HAP provides a survey of activities
across a broad range of energy requirements. The activity items are
ranked based on estimated metabolic equivalents, i.e., the approximate
amount of oxygen consumed by an average person at rest, with
item 1 being the activity requiring the least energy expenditure and
item 94 requiring the greatest energy expenditure. For each item, the
respondent indicates whether he or she is still doing, has stopped
doing, or never did the activity. The Maximum Activity Score (MAS)
is the highest oxygen-demanding activity that the respondent still
performs. The Adjusted Activity Score (AAS) is determined by subtracting
from the MAS the total number of activities the respondent
has stopped doing that have numbers lower than the MAS. The AAS
is interpreted as a measure of usual physical activity level.
Other variables are obtained from the CDS or from the ME form
(2728). Vascular access type was ascertained directly from CDS participants.
The Medical Outcomes Study Short Form 12-item survey
(SF-12) was administered in its entirety as part of the CDS Patient
Questionnaire. Self-reported physical functioning was assessed
using the Physical Component Summary (PCS) score of the SF-12.
Under the direction of the Nutrition Special Studies Center,
serum specimens were obtained in conjunction with routine
monthly laboratory studies for the subset of CDS participants
chosen to participate in the Nutrition substudy. One 15 ml tube
of blood was drawn for serum isolation and then shipped on dry
ice via overnight delivery to the laboratory in Davis, California.
Serum was separated upon receipt and aliquoted for analysis and
for storage in a repository. One aliquot was analyzed for C-reactive
protein (CRP), prealbumin, albumin, and alpha 1 acid glycoprotein
(AAG) by rate nephelometry using a Beckmann Array nephelometer.
All nephelometric measures were made in duplicate in
each of two optical systems. The average of these values is used
for calculations.
Physical activity level is compared between or among groups
using Mann-Whitney U tests for two groups or Kruskal Wallis
one-way analysis of variance for three or more groups. Differences
reported in the text are based on a two-sided p-value of less than 0.05.
Providers
Chapter Ten; J tables
The USRDS continues to use its new definition of a dialysis chain.
Throughout the atlas and in Reference Section J, we now define a
chain-affiliated unit as one of a group of 20 or more freestanding
dialysis units which are owned or operated by a corporation at the
end of a year. The affiliation category of “small dialysis organization,”
or SDO, includes all organizations meeting our definition of
a chain but having 20 or more but fewer than 100 units.
In previous years, chain affiliation was determined from the
“Provider Name” field of the CMS Annual Facility Survey, the “Chain
Name” field of the CMS Dialysis Facility Compare database, and the
“Chain Organization Name” field of the CMS Independent Renal
Facility Cost Report. Currently, however, it is determined solely
from the “Provider Name” field of the Facility Survey.
Data are obtained from the Facility Survey (for 1988–2007), the
Cost Report (Form 265-94, for 1994–2000), the CMS Dialysis Facility
Compare (DFC) database (for 2001–2007), and the CDC National
Surveillance of Dialysis-Associated Diseases in the United States
(for 1988–2002, excluding 1998, when the CDC did not conduct a
survey). The CDC discontinued the National Surveillance of Dialysis-
Associated Diseases after 2002. In 2007, there were 5,240 facilities
in the Facility Survey.
A facility’s hospital-based or freestanding status is determined
from the third and fourth digits of the provider number assigned
to each dialysis unit by CMS. For years prior to 2002, we determine
facility profit status through the ownership type field on the
CMS survey. In the 2002 CMS survey the profit status variable was
dropped, so for that and subsequent years we use the profit status
field of the DFC. There are, however, a small number of facilities
in the CMS survey that are not in the DFC database; these facilities
have an unknown profit status, and are omitted from any graph
showing profit status.
For provider-specific analyses, unless otherwise specified, the
dialysis provider for individual patients is assigned as follows: for
prevalent studies, the patient is assigned to the facility providing
dialysis services at the prevalent date, as determined from the treatment
history. For incident analyses, the patient is assigned to the
facility providing dialysis services at the incident date, as determined
from the treatment history. In either case, if provider data
are unavailable from the patient’s treatment history, the patient is
assigned to “unknown provider” or excluded, depending on the
analysis.
ANEMIA TREATMENT & VASCULAR ACCESS
Figure 10.5 includes period prevalent dialysis patients in 2002 and
2007. Data for mean hemoglobin include only patients with valid
EPO claims. A mean is calculated for each patient from all valid
claims during the year. Chain affiliation is defined at the final patient
claim of the year.
Figure 10.6 illustrates the prevalence of IV iron administration,
by dialysis unit affiliation and product type. The cohort consists of
patients initiating ESRD therapy at least 90 days prior to the start
of 2007, and receiving dialysis on December 31, 2006. All patients