Primary intrinsic and/or acquired drug resistance is the main underlying cause of failure in cancer treatment.
Natural deaths were categorized by their primary or underlying cause into renal, nonrenal natural death and cardiovascular death, as described previously [ 17].
Physicians are asked to give up to 4 causes of death, with one of them being the "primary" or "underlying" cause that started the chain of events leading to death.
Secondary analysis of data from 1996 to 2006 on the "primary" or "underlying" cause of death from official death certificates filled out by physicians and additional data from 2003 to 2006 on the place of death from these certificates.
The primary outcome was underlying cause of death, coded according to the International Classification of Diseases (ICD), 10th revision (15), using Iris version 4.2.0, the same software that the SNBHW employs for the CDR.
In analyses where cases were restricted to participants for whom diverticular disease was the primary diagnosis or underlying cause of death (n=531 cases included), the relative risk for vegetarians or vegans versus meat eaters was 0.72 (0.55 to 0.95), and the risk for the highest versus the lowest fifth of dietary fibre intake was 0.61 (0.44 to 0.84; P=0.002 for trend).
There are primary (or underlying) causes of death, followed by secondary and tertiary ones, and the clerk on duty may take a dislike to one of them.
New codes were introduced to account for frequent combination of primary and underlying causes.
Consequently, population-based survival studies are usually not able to consider the site of metastasis and even death certificates give the primary cancer as an underlying cause of death.
Finally, metformin levels are not linked to mortality in those who develop lactic acidosis, perhaps reflecting the primary effect of the underlying cause of the acidosis (e.g., hypoxia, hemodynamic compromise) on outcomes rather than incriminating metformin itself (33– 33).
