Venous Thromboembolism (VTE) Risk Factors among Nursing Home Residents: A Population-Based Case-Control Study.

Abstract

Confinement to a nursing home (NH) is an independent risk factor for VTE and accounts for 13% of all VTE occurring in the community, but the question of which NH residents are at risk is largely unanswered.Objective: To determine VTE risk factors among NH residents.Methods: Using the Minnesota State Case Mix Review Program Public Research Files, we performed a case-control study of all Olmsted County, MN NH patients with an ICD-9 code-identified diagnosis of VTE from 1988–1994. From the same source, we identified one age-, sex-matched control and used conditional logistic regression to estimate odds ratios for an association of VTE with 46 characteristics assessed in the Minnesota Case Mix data.Results: Univariate associations between characteristics and odds of VTE are described below. Significantly increased odds were observed for residents assessed following hospitalization (a nearly 4-fold increase, p=0.002, Table) and residents considered incapable of self-preservation (i.e., unable to cope with potentially harmful situations) (> 2.0 fold increase, p=0.03). Non-significant 2–3 fold increased odds were observed for limitations in certain specific Activities of Daily Living (ADL) (including walking and dressing) and for limitations in more than 3 ADLs. Similar increased odds were observed for residents using a wheelchair, taking more than 3 oral medications, enrolled in professional activity programs, and needing behavior management.Conclusions: Need for assistance (especially problems with immobility), lack of self preservation, and recent hospitalization may identify a subset of NH residents that are at especially high VTE risk and who may warrant consideration of prophylaxis.Univariate VTE Risk Factors for Nursing Home ResidentsCharacteristicOdds Ratio95% CIP-valueOral medications > 33.000.97-9.300.06Activities of Daily LivingHigh/Medium (4-8) vs. low (0-3)2.200.76-6.330.14Help dressing2.750.88-8.640.08Help walking3.000.61-14.860.18Wheelchair use2.500.97-6.440.58Needs behavior management3.000.62-14.860.18Help toileting2.000.68-5.850.20Lack of self-preservation2.331.07-5.100.03Transfer from hospital3.861.68-8.860.0015Anti-depressant drugs0.500.19-1.330.16Professional activity program2.250.69-7.30.18