Table 4

Results of Cox proportional hazards model for therapy discontinuation

Study population (N = 48,212)

Variable

Hazards ratio

p-value

Age

0.989

<.0001*

Female

1.048

0.0002*

RxRisk categories^a

Anxiety and Tension, Bipolar Disorder, Depression, Psychotic Illness, ADD

1.079

<.0001*

Asthma, Allergic Rhinitis

1.031

0.1891

Cardiac Disease, Coronary & Peripheral Vascular Disease, Heart Disease, Hypertension^b

0.973

0.2432

Gastric acid disorder, IBS

1.004

0.8477

Rheumatoid Arthritis, Gout

1.147

<.0001*

Thyroid Disease

0.951

0.0426*

Diabetes

1.158

<.0001*

Business Type

HMO

N/A

N/A

Medicaid

1.339

<.0001*

Medicare

1.451

<.0001*

Self

1.056

0.0013*

Concomitant Other CVD-related Medications Used

Digitalis

1.138

0.0086*

Nitrates

1.224

<.0001*

Antiplatelet Medications

1.097

0.0502

Antihyperlipidemic Medications

0.797

<.0001*

Average copay^c

1.001

0.3831

Target medication classes^d

ARB/HCTZ

0.529

<.0001*

ACEI/HCTZ

0.536

<.0001*

BB/HCTZ

0.532

<.0001*

* Significant p-value

^a RxRisk categories shown in this table include the 7 most frequent disease states in the study cohort. All RxRisk disease categories were included in the model.

^b This RxRisk category does not include the target medications, digitalis, nitrates, antiplatelet medications or antihyperlipidemics.

^c Limited to HTN medications of the same class as the index drug.

^d Reference Medication Class = HCTZ

Patel et al. BMC Family Practice 2008 9:61   doi:10.1186/1471-2296-9-61