In addition, there is no specific ICD-9 or other procedure code that indicates a Norwood procedure, and therefore case definitions varied by study.
This is an important finding as the outbreak may have begun in September and therefore, case investigations and institution of infection control measures to prevent transmission events and environmental contamination with C. difficile, could have been initiated earlier.
However, this information is not routinely available from NHS 24 and therefore case-mix adjustment was only possible using the age and sex of the patient, and the time of the call.
41 However, sentences are longer in the USA, 42 so fewer treatments may be interrupted, and therefore case-finding in US prisons could be more cost-effective than our results indicate.
One possible explanation for this heterogeneity is that the BCAC is largely composed of prevalent cases, as compared to only incident cases in the NHS, and therefore case-specific variables which may effect the association between this polymorphism and breast cancer risk overall could have different distributions in the BCAC as compared to the NHS.
However, some age-sex combinations could not be recruited into the study for the poisoning case group (i.e., females aged 1 and 3 years); therefore, cases and controls were not matched as planned.
a In three cases, re-perforation occurred and, therefore, these cases are not included.
In this case and therefore for case 1.
To have 90% power to detect this odds ratio as significant would require 259 discordant pairs and therefore 719 cases with one control per case [ 26].
Therefore, cases and controls were recruited from the same place.
