19 deaths recorded at DaVita lufkin unit in five months before closure

There is a new Lufkin Daily News article by Jessica Savage announcing Feds release DaVita patient death numbers (for background see RenalWeb's Lufkin DaVita news summary):

Nineteen patient deaths occurred at DaVita Lufkin Dialysis in a five-month period ending in April before its temporary closure, according to a survey released Monday by the U.S. Department of Health and Human Services through an open records request.

A five month period ending in April would be December 1, 2007 through April 30, 2008; further into the article it is reported that:

The facility had a 7.1 percent higher patient death rate in 2007 than the state average, at 27 percent from the state's 19.9 percent, according to the report. Twenty-five patient deaths occurred between Jan. 1 - Dec. 31, 2007, the report stated.

There is overlap between the two periods. It isn't clear how many of the 19 people in the DHHS report died in December. Using the numbers given there were 25 deaths in 2007 when about 18 would have been expected. This then means the expected per month death rate (if the census was stable) would be about 1.5 per month (25/.27 = equals the 2007 patient years in the census : 92.5; 92.5 x .199 = expected number of deaths at Texas average; 18) in the last five months of operation they had 19 deaths or nearly 4 per month. By the averages 11 people died above what would be expected. One important question about the numbers: do they include people in the first three months of treatment?

Typically people who die in the first three months of treatment are not counted in the official unit mortality numbers. This is a standard in the industry but in this special investigation it may be that all deaths were counted, however I don't think that can be assumed. How did those just starting dialysis fare at the unit ? While the numbers suggest possibly 10 or more excess deaths the reports to date indicate the nurse is  suspected by DaVita in four deaths, while the Lufkkin police department hasn't released a statement about potential murder or manslaughter charges.

There are many questions left to answer but the number suggests a dreadful crime was committed. If ten or more deaths are attributable to Saenz (the arrested nurse) this murder spree puts her on the all time serial killer list between Jack the Ripper and Charles Manson.