The figure shows the means and the distribution computed as the
kernel probability density for male and female heterozygotes (het),
Rh-positive homozygotes (hom), and Rh-negative homozygotes (neg).
Post hoc ANCOVA tests with physical health problems score as the
dependent variable performed separately for women and men showed
significantly worse health in Rh-positive female homozygotes than
Rh-negative female homozygotes (p = 0.026, eta2 =
0.053, beta = -0.225) and Rh-positive female heterozygotes (p = 0.047,
eta2 = 0.030, beta = 0.170). No other difference
between Rh genotypes was significant either for physical or mental
health problems score.
To see which specific health problems were responsible for the observed
effect of the Rh genotype, we performed a partial Kendall correlation
test controlled for age for all source variables originally used for
computing physical and mental health problems scores. Table 2 shows
that, generally, heterozygotes have better health than Rh-positive
homozygotes. In women, Rh-negative homozygotes had better health than
Rh-positive homozygotes and often also than heterozygotes while the
opposite is true for men. However, the general pattern also had some
exceptions. For example, heterozygotic men scored better in most
parameters of physical and mental health than Rh-positive homozygotes
but they reported suffering from more chronic problems and consuming
more medical drugs currently.
To be able to compare our results with those already published, we
pooled Rh-positive homozygotes and heterozygotes and repeated the
analyses with the binary variable Rh-positivity instead of nominal
variable Rh genotype (Fig. 2). ANCOVA tests showed no significant effect
of Rh phenotype or Rh phenotype-sex interaction on the scores of mental
or physical health problems (physical health-sex-Rh: p = 0.103,
eta2 = 0.010; mental health-sex-Rh phenotype: p =
0.912, eta2 < 0.0001). However, partial
Kendall analyses showed several significant effects of Rh phenotype on
the source of physical and mental health-related variables. Generally,
Rh-positive women reported worse and Rh-positive men better health than
their Rh-negative peers (Table 2).
Tab. 2 . Effects of Rh genotype and phenotype on physical and
mental health problems scores and their source variables