cass2 {twostage}R Documentation

The CASS pilot dataset with sex and categorical weight as auxiliary variables

Description

This is a pilot dataset from the Coronary Artery Surgery Study (CASS) register (Reilly, 1996). It consists of a random sample of 10 observations from each of the strata defined by different levels of mortality, sex and weight category. The "first-stage" data from which this pilot sample was chosen had 8096 observations. There are ten variables in the pilot dataset (see FORMAT).

Format

The dataset has 118 observations with 10 variables arranged in the following columns:

Column 1 (Mortality)
The operative mortality of the patients
(0 = Alive, 1 = Dead)

Column 2 (sex)
(0 = Male, 1 = Female)

Column 3 (Categorical Weight)
1 = weight less than 60 kg
2 = weight between 60-70 kg
3 = weight 70 kg or more

Column 4 (weight)
The actual weight (in Kg) of the patients at the time of bypass surgery

Column 5 (age)
Age of patients at the time of bypass surgery

Column 6 (Unstable angina)
The angina status of the patients at the time of bypass surgery
(0 = Stable, 1 = Unstable)

Column 7 (Congestive Heart Failure Score (CHF) score)

Column 8 (Left ventricular end diastolic blood pressure (LVEDBP))

Column 9 (Urgency of Surgery)
(0 = Not urgent, 1 = Urgent)

Column 10 (the auxiliary variables, Z)
Different values describe the different levels of sex and weight category

1 = Male; weight less than 60 kg
2 = Male; weight between 60-70 kg
3 = Male; weight 70 kg or more
4 = Female; weight less than 60 kg
5 = Female; weight between 60-70 kg
6 = Female; weight 70 kg or more

Source

Vliestra, et.al. (1980)

References

Reilly,M. 1996. Optimal sampling strategies for two-stage studies. Amer. J. Epidemiol. 143:92-100

Vliestra,R.E.,Frye R.L., Kromnal R.A.,et.al.(1980). Risk factors and angiographic coronary artery disease: a report from the Coronary Artery Surgery Study (CASS). Circulation 62:254-61

See Also

msnprev,fixed.n, budget,precision, cass1,cass2,coding


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