Contents of It's not All in Your Head by Asmundson and Taylor

treatment participants would have only read the psychoeducational information about
health anxiety and apparently that was enough to initiate some decreases in health
anxiety, reassurance seeking, preoccupation with body sensations, and depression.
However, because power was so low the confidence in these finding is limited.
Half of the SHB participants (n = 5) received in-person check-ins with facilitators
and were given the entire self-help book at the beginning of treatment. The remaining 5
received telephone check-ins with the Head Researcher and were mailed Part 1, Part 2,
and Part 3 of the self-help book separately. Although independent samples t- tests had
non-significant results, the small sample size made the results uncertain and open to Type
II error (i.e., reporting that there were no differences when there actually were
differences). Therefore, it could not be determined statistically if check-in format had an
effect on treatment results.
3.1.4. SHB and WLC between-group comparisons
There were almost no differences between the SHB and WLC groups on the
primary and secondary measures at T1 (see Table 5). The one exception was that the
WLC group had higher scores on the SF-36 MCS than the SHB group (t = -3.06, df = 12,
p = .005; power = .99 [high power]). This suggests the WLC group believed they had
better mental health at T1 than the SHB group. The absence of other significant
differences may have occurred because of the small sample size and lack of statistical
power. This makes it uncertain whether or not the two groups were equivalent at T1.
60