Venous Thromboembolism After Joint Replacement in Older Veterans with Comorbidity

1Boston University School of Medicine, Boston, MA
2Edith Nourse Rogers Memorial VA Hospital, Bedford, MA
3Brigham and Women's Hospital, Boston, MA
4Boston University School of Public Health, Boston, MA

Meeting: Hospital Medicine 2012, April 1-4, San Diego, Calif.

Abstract number: 97631


Venous thromboembolism (VTE) is a common and costly complication of total hip and knee replacement (THR and TKR). Although potent prophylaxis regimens now exist to significantly reduce the risk of VTE, their wide spread adoption has been slow due to an increased risk of bleeding. Identifying a high risk population such as older adults with comorbidities or poor functional status who would benefit most from high potency prophylaxis would improve the way we make decisions about prophylaxis.


Using VA administrative data, we identified older adults who underwent THR or TKR from 2002–2009. The primary outcome measure was VTE, including deep venous thrombosis and pulmonary embolus. Using logistic regression, we analyzed the independent effect of cardiopulmonary comorbidities on VTE. Secondarily, we analyzed functional status expressed in a summary physical component score (PCS) in a subset of patients for whom it was available.


There were 24,051 THR and TKR surgeries performed at the VA during the study period. COPD predicted a 24% increase in VTE (OR=1.24, 95% CI 1.06–1.45). Low values of PCS, which was available for 3256 patients, demonstrated a trend of increased risk of VTE (lowest quartile OR =1.65, 95% CI 0.96–2.85 compared with highest quartile).


COPD predicted a small increase in VTE whereas low functional status appeared to increase the odds of VTE substantially. Our findings suggest that cardiopulmonary comorbidities should not be factored into decisions about prophylaxis but that functional status probably should be assessed. More definitive conclusions about the role of these comorbidities and functional status are limited by typical constraints of administrative data analysis.

Table 1Independent Effects of Single Comorbidities, Demographics, and Functional Status in a Multivariate GEE Model* Predicting Postoperative VTE

  Comorbidity Model N=24,051 Comorbidity Model with PCS N=3,256
Exposure Odds Ratio 95% CI Odds Ratio 95% CI
CAD (vs. no CAD ) 0.98 0.84–1.15 1.03 0.64–1.68
CHF 1.17 0.91–1.51 1.23 0.5–3.06
COPD 1.24 1.06–1.45 0.99 0.59–1.67
CVD 0.88 0.57–1.35 1.31 0.57–3.02
DM 0.77 0.64–0.92 0.89 0.56–1.4
Age >=79 (vs. 65–69 reference) 1.13 0.93–1.37 1.29 0.66–2.55
Age >=74 to 79 1.11 0.93–1.32 1.31 0.74–2.31
Age >69 to 74 0.95 0.79–1.14 1.75 0.97–3.15
Female gender (vs. male) 1.33 1.07–1.82 0.68 0.17–2.71
Black (vs. Caucasian reference) 1.39 1.07–1.82 1.48 0.72–3.01
Hispanic 0.34 0.11–1.04 2.19 0.35–13.6
Other ¥ 1.04 0.87–1.23 1.06 0.6–1.88
PCS 2–23 ( vs. 39–64 ref)     1.65 0.96–2.85
PCS 24–31     1.50 0.85–2.64
PCS 31–38     1.28 0.67–2.46
Abbreviations: CAD coronary artery disease, CHF congestive heart failure, COPD chronic obstructive disease, CVD cerebrovascular disease, DM diabetes mellitus; CI confidence interval *Adjusting for surgery type (hip vs. knee and primary vs. revision), other health conditions (including obesity, malignancy, hypertension, prophylaxis regimen, facility knee and hip surgery volume, anesthesia type, income) ; preoperative medications not included in Comorbidity with PCS Model due to problems with model convergence; in a sensitivity analysis on the results from the main Comorbidity Model, inclusion of preoperative medications did not change the effects reported. ¥Other includes Asian, other, and not reported

To cite this abstract:

Kapoor A, Berlowitz D, Hylek E, Cabral H, Katz J, Chew P, Silliman R. Venous Thromboembolism After Joint Replacement in Older Veterans with Comorbidity. Abstract published at Hospital Medicine 2012, April 1-4, San Diego, Calif. Abstract 97631. Journal of Hospital Medicine. 2012; 7 (suppl 2). Accessed May 26, 2019.

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