Table 3.

Analysis of factors associated with latent period.^a

Source	DOF	Type I SSb	Mean Square	F Value	P-valuec
Age at first exposure, years	1	231.46	231.46	13.52	<0.01
Smoking	2	172.08	86.04	5.02	<0.01
Average frequency of visits to the doctor, per 2 years	1	160.10	160.10	9.35	<0.01
Bone marrow dose, mGy	1	0.69	0.69	0.04	0.84
Source	DOF	Type III SSd	Mean Square	F Value	P-valuee
Age at first exposure, years	1	135.86	135.86	7.93	<0.01
Smoking	2	126.85	63.43	3.70	0.03
Average frequency of visits to the doctor, per 2 years	1	158.40	158.40	9.25	<0.01
Bone marrow dose, mGy	1	0.69	0.69	0.04	0.84

Abbreviations: DOF, degrees of freedom; SS, sum of squares.

^aFor 74 CLL cases with available information on smoking.

^bIndicates the reduction in the sequential error sum of squares with addition of each variable.

^cP-value from the analysis of covariance adjusted for all variables above the test variable.

^dIndicates error sum of squares computed by comparing the full model to the model without the test variable.

^eP-value from the analysis of covariance adjusted for all other factors in the Table.