In England, there is a commonly held belief that it is unsafe to be admitted to the hospital on “Black Wednesday”, the first Wednesday of August. Each year, this is the day when the group of newly certified doctors begin working in National Health Services (NHS) hospitals. One study compared the likelihood of death for patients who are admitted in the final Wednesday of July, with patients who were admitted in the first Wednesday in August. This study found that there is a 6% higher mortality rate for patients who are admitted on Black Wednesday.
There are 1600 hospitals and specialist care centres that operate under the NHS. Each centre routinely collects administrative data when admitting their patients. A group did a retrospective study using the archived hospital admissions data from 2000 to 2008. Each year, over 14 million records are collected. Two cohorts of patients were tracked: one group being patients who were admitted as emergency—unplanned and non-elective patients in the last Wednesday of July. The second cohort comprised of patients who were admitted as emergency patients in the first Wednesday of August. Patients who were transferred were taken into consideration to avoid double counting.
Each cohort was then tracked for one week. If the patient had not died by the following Tuesday, they were considered alive. Otherwise, if they had passed away by the following Tuesday, it was counted as a death. The study only tracked patients for one week, because it was deemed to be the best method to “capture errors caused by failure of training or inadequate supervision”, on the part of the junior doctors. Having a short-term study also avoided any possible biases that may arise from seasonal effects that would complicate the analyses.
The study only analyzed emergency admissions to ensure randomness in the data. They wanted to avoid bias that could have resulted from differences in planned admissions due to administrative pressures.
After considering both cohorts, the study analyzed 299741 hospital admissions, with 151844 admissions in the last week of July, and 147897 in the first week of August. They found that there were 4409 deaths in total, with 2182 deaths in the last week of July, and the last week of August.
The study found small, non-significant differences in the crude odds ratio of death between the two cohorts. However, after adjusting for the year, gender, age group, socio-economic deprivation, and co-morbidity of the patients, it was found that patients who were admitted on Black Wednesday had a 6% higher risk of mortality. The 95% confidence interval ranged from 1.00 to 1.15, and the p value was 1.05.
In short, for hospitals in the NHS from 2000 to 2008, it was found that there was a small, but still statistically significant, increase in the risk of death for patients who were admitted on Black Wednesday, over patients who were admitted the week prior.