There was no evidence of systematic difference between session lengths or treatment frequency between participating centres (Kruskal-Wallis P=0.57).
First, exploiting the variation across countries, rather than between participating and non-participating firms within countries, avoids the selection problem that characterises firm-level studies.
Differences between participating and non-participating GPs were tested with t-tests or chi-square tests.
Differences between participating and non-participating cancer patients were tested with χ.
We will compare the differences between participating and non-participating patients.
There were no differences in patients' socioeconomic status between participating and non-participating hospitals.
GP characteristics were compared between participating and non-participating GPs by using standard (Pearson's) Chi-squared test.
The findings, which used small-area census data to investigate differences between participating and non-participating subjects, are reported here.
There were no significant differences in gender between participating and non-participating subjects among AS patients and population controls.
No significant differences were found in gender, birth weight and gestational age between participating and non-participating children.
Bulk milk PCR-positivity did not differ between participating and non-participating farms, 24.4% and 22.8%, respectively.
