RT Journal
A1 Cooper SP, Griffith JA
T1 DRowning mortality in los angeles county
JF JAMA
JO JAMA
YR 1989
FD February 24
VO 261
IS 8
SP 1154
OP 1154
DO 10.1001/jama.1989.03420080068031
UL http://dx.doi.org/10.1001/jama.1989.03420080068031
AB To the Editor.— 
    O'Carroll and colleagues1 presented an important population-based study on deaths due to drowning in Los Angeles County from 1976 to 1984; however, their calculation of death rates may have been erroneous. They correctly point out that there is geographic variability in death rates due to drowning across the United States. It is therefore essential that the calculation of rates be comparable across studies and be described adequately in "Methods" sections of research reports.It seems that the study by O'Carroll et al calculated average annual death rates due to drowning by including in the numerator the number of deaths recorded in the Los Angeles County Coroner's Office during the 9 years and in the denominator the resident population census data (multiplied by 9 years). However, it is important to distinguish between place of occurrence of death and residence at the time of death. Although their "Methods"