12.2 Demographics table

First, let’s look at associations between our explanatory variable of interest (exposure) and other explanatory variables.

TABLE 12.1: Exporting ‘table 1’: Tumour differentiation by patient and disease factors.
label levels Well Moderate Poor p
Age (years) Mean (SD) 60.2 (12.8) 59.9 (11.7) 59.0 (12.8) 0.644
Sex Female 51 (54.8) 314 (47.4) 73 (48.7) 0.400
Male 42 (45.2) 349 (52.6) 77 (51.3)
Extent of spread Submucosa 5 (5.4) 12 (1.8) 3 (2.0) 0.081
Muscle 12 (12.9) 78 (11.8) 12 (8.0)
Serosa 76 (81.7) 542 (81.7) 127 (84.7)
Adjacent structures 31 (4.7) 8 (5.3)
Obstruction No 69 (74.2) 531 (80.1) 114 (76.0) 0.655
Yes 19 (20.4) 122 (18.4) 31 (20.7)
(Missing) 5 (5.4) 10 (1.5) 5 (3.3)
nodes Mean (SD) 2.7 (2.2) 3.6 (3.4) 4.7 (4.4) <0.001

Note that we include missing data in this table (see Chapter 14).

Also note that nodes has not been labelled properly.

In addition, there are small numbers in some variables generating chisq.test() warnings (expected fewer than 5 in any cell).

Now generate a final table.

TABLE 12.2: Exporting ‘table 1’: adjusting labels and output.
Exposure: Differentiation Well Moderate Poor p
Age (years) Mean (SD) 60.2 (12.8) 59.9 (11.7) 59.0 (12.8) 0.644
Sex Female 51 (54.8) 314 (47.4) 73 (48.7) 0.400
Male 42 (45.2) 349 (52.6) 77 (51.3)
Extent of spread Submucosa 5 (5.4) 12 (1.8) 3 (2.0) 0.081
Muscle 12 (12.9) 78 (11.8) 12 (8.0)
Serosa 76 (81.7) 542 (81.7) 127 (84.7)
Adjacent structures 31 (4.7) 8 (5.3)
Obstruction No 69 (74.2) 531 (80.1) 114 (76.0) 0.655
Yes 19 (20.4) 122 (18.4) 31 (20.7)
(Missing) 5 (5.4) 10 (1.5) 5 (3.3)
Lymph nodes involved Mean (SD) 2.7 (2.2) 3.6 (3.4) 4.7 (4.4) <0.001