Table 2.
Associations of variables with heparin dose for maintenance hemodialysis in older U.S. patients expressed as changes in heparin dose from a multivariable mixed effects model with random intercept for facility.1 N=17,722
| Variable | Coefficient estimate (units of heparin) | 95% Confidence interval (units of heparin) |
|---|---|---|
| Patient characteristics | ||
| Demographics | ||
| Age (per year) | −20 | (−25, −14) |
| Male (vs. female) | 145 | (80, 209) |
| Race | ||
| Black | 103 | (20, 185) |
| White | Reference | Reference |
| Other | −76 | (−224, 72) |
| Hispanic ethnicity | 79 | (−75, 155) |
| Reported comorbidities | ||
| Arrhythmia | −109 | (−176, −42) |
| Cancer | 10 | (−76, 95) |
| Coronary artery disease | −94 | (−158, −30) |
| Deep vein thrombosis | 25 | (−81, 130) |
| Diabetes mellitus | 9 | (−54, 72) |
| Gastrointestinal bleeding | −244 | (−347, −140) |
| Heart failure | −84 | (−145, −22) |
| Hemorrhagic stroke | −214 | (−528, 101) |
| Ischemic stroke | −87 | (−165, −9) |
| Liver disease | −111 | (−256, 34) |
| Peripheral vascular disease | −4 | (−67, 58) |
| Pulmonary disease | 92 | (22, 163) |
| Pulmonary embolism | −131 | (−390, 127) |
| Warfarin use | −288 | (−457, −118) |
| Vital Signs and laboratory measurements | ||
| Weight (kg) by quartile | P for trend<0.001 | |
| <61 | Reference | Reference |
| 61–71.4 | 385 | (300, 470) |
| 71.5–83 | 678 | (588, 768) |
| >83 | 1430 | (1332, 1527) |
| Pre-dialysis systolic blood pressure (mmHg) | P for trend=0.13 | |
| <120 | 84 | (−11, 178) |
| 120–139 | Reference | Reference |
| 140–159 | −20 | (−99, 58) |
| ≥160 | −10 | (−89, 69) |
| Hemoglobin (g/dL) | P for trend=0.001 | |
| <9 | −375 | (−621, −129) |
| 9–9.9 | −142 | (−292, 8) |
| 10–10.9 | −122 | (−215, −28) |
| 11–11.9 | Reference | Reference |
| 12–12.9 | 37 | (−35, 110) |
| 13–13.9 | 77 | (−20, 174) |
| ≥14 | 285 | (128, 442) |
| Platelets (x103/μL) | P for trend<0.001 | |
| <150 | −513 | (−613, −413) |
| 150–229 | −225 | (−294, −157) |
| 230–310 | Reference | Reference |
| 311–400 | 137 | (39, 234) |
| >400 | 188 | (36, 341) |
| Albumin (g/dL) | P for trend=0.39 | |
| <2.5 | 1 | (−288, 291) |
| 2.5–2.9 | 51 | (−103, 204) |
| 3–3.4 | Reference | Reference |
| 3.5–3.9 | −8 | (−89, 73) |
| ≥4 | −80 | (−171, 12) |
| Dialysis characteristics | ||
| Vascular access used during index session | ||
| Fistula or graft | Reference | Reference |
| Central venous catheter | 1391 | (1321, 1461) |
| Length of session (minutes) | P for trend<0.001 | |
| <180 | −712 | (−876, −548) |
| 180–194 | −278 | (−389, −168) |
| 195–209 | Reference | Reference |
| 210–224 | 301 | (196, 406) |
| 225–239 | 615 | (482, 747) |
| ≥240 | 1068 | (951, 1186) |
| Reuse of dialysis filter | 502 | (419, 585) |
| Years on dialysis (per year) | 1 | (−11, 9) |
| Facility characteristics | ||
| Number of outpatient hemodialysis patients (by quartile)2 | P for trend=0.04 | |
| <54 | Reference | Reference |
| 54–74 | −182 | (−351, −14) |
| 75–105 | −164 | (−348, 21) |
| ≥106 | −141 | (−350, 67) |
| Urban (vs. rural)3 | −276 | (−442, −111) |
| Census division4 | Pwald<0.001 | |
| East North Central | 848 | (426, 1270) |
| East South Central | 1440 | (973, 1908) |
| Middle Atlantic | 86 | (−348, 520) |
| Mountain | 840 | (374, 1307) |
| New England | Reference | Reference |
| Pacific | 780 | (360, 1200) |
| South Atlantic | 792 | (391, 1194) |
| West North Central | 1357 | (902, 1812) |
| West South Central | 923 | (499, 1346) |
All of the variables listed were included in the model. P for trend was calculated treating the categorical variable as an ordinal variable.
Reflects the number of outpatient hemodialysis patients treated at a facility at the end of 2008, per the ESRD Facility Survey (form CMS-2744).
Facilities were considered urban if they were classified as a metropolitan area in the Rural-Urban Commuting Area (RUCA) Codes version 2.0, which are based on 2000 Census commuting data and 2004 zip codes; all other areas were considered to be rural.
Facilities were categorized into one of nine U.S. Census Bureau Divisions based on their state.31