| Detecting Social Change |
between two variables within categorical data. It
demonstrates an association between variables
and whether the outcome is statistically significant
(Fletcher and Lock 2005, 125). When the outcome
of the Chi-squared method is close to zero then there
is no evidence of association (Fletcher and Lock
2005, 131). There is a significant relation between
evidence when the result is equal to or larger than χ 2
= 3.84 (Fletcher and Lock 2005, 202). Results were
determined to be statistically significant when the
P-value was equal or below the 0.05 level.
Results
In total, the data from 9556 individuals analysed
by MOLA were available for this research. From
the nine Medieval cemeteries included in the
WORD database and monographs, 6060 adults
were analysed of which nine individuals showed
skeletal changes conforming osteoporosis. Of the
sixteen post-Medieval cemeteries evaluated, which
contained 3496 adults, 76 individuals show skeletal
changes diagnosed as (possible) osteoporosis. The
distribution per site of males and females of different
ages affected with osteoporosis can be found in the
previous mentioned overview tables: 1a and 1b.
The CPR calculated for the Medieval period is 0.07%.
Three of the sites contained zero individuals with
in their excavated population with osteoporosis.
The calculated CPR for the post-Medieval period
is higher with 1.08%. Five cemeteries contained
no individuals with osteoporosis. However, four
post-Medieval cemeteries exceed this average
post-Medieval CPR with large numbers. These
cemeteries are: St Benet Sherehog (post-Medieval
graves) with 2.55%, Chelsea Old Church with
3.79%, St Bride’s Church Fleet Street with 3.96%
and St Brides Lower Cemetery with 5.16%. Overall,
the result of the Chi-squared test demonstrated
prevalence of osteoporosis between the samples
from the two periods (P-value = < 0.0001, χ 2 =
100.879, 1df). These results demonstrate that here
is more osteoporosis in the post-Medieval period.
Since osteoporosis can be linked to sex, it is useful
to look at statistical differences between males and
females with osteoporosis in the Medieval and post-
Medieval period. However, the number of affected
adults in the Medieval period is too small to make
any meaningful comparisons. The result for the
post-Medieval period (tab. 2a) shows an extremely
and osteoporosis (P-value = < 0.0001, χ 2 = 33.707,
1df). This indicates that females are more affected
with osteoporosis than males in this period.
post-Medieval Males
post-Medieval Females
Total
OP No OP Total
57 1183 1240
14
71
1459
2642
1473
2713
Table 2a. Contingency table for analysed males and
females from the post-Medieval period.
Medieval Males
OP No OP Total
14 1459 1473
3
post-Medieval Males
Total
17
3253
4712
3256
4729
Table 2b. Contingency table for analysed males with
osteoporosis between periods.
Medieval Females
post-Medieval Females
Total
OP No OP Total
57 1183 1240
5
62
2142
3325
2147
3387
Table 2c. Contingency table for analysed females with
osteoporosis between periods.
To assess if one or both sexes were more or less
affected, prevalence rates were calculated for each
sex. To assess whether osteoporosis prevalence
rates differed between Medieval and post-Medieval
males, their prevalence rates were compared (tab.
(P-value = < 0.0001, χ 2 = 18.531, 1df). The
relationship for females with osteoporosis (tab. 2c)
between the Medieval and post-Medieval period
2
=
80.887, 1df). This suggests that both sexes are more
affected with osteoporosis in the post-Medieval
period.
post-Medieval
36-45 Years
post-Medieval
≥46 Years
Total
OP No OP Total
59 683 742
6
65
650
1333
656
1398
Table 2d. Contingency table for individuals with osteopo-
rosis in two different age categories for the post-Medieval
period.
2017 | INTER-SECTION | VOL III | p.33