Citation(s) from the GunPolicy.org literature library
CDC. 2014 ‘Questions About Death Rates - Data Unreliable.’ CDC WONDER Online Database - Underlying Cause of Death, Results. Atlanta, GA: Centers for Disease Control and Prevention / CDC, National Center for Health Statistics. 5 January
1) Questions About Death Rates - Data Unreliable
g) Why are death rates sometimes flagged as "Unreliable" or "Suppressed"?
Death rates based on counts of less than twenty… are flagged as "Unreliable". A death rate based on fewer than 20 deaths has a relative standard error (RSE(R)) of 23 percent or more. A RES(R) of 23 percent is considered statistically unreliable.
Death counts and death rates are "Suppressed" when the data meets the criteria for confidentiality constraints. See Assurance of Confidentiality for more information.1