Recent articles in this journal have questioned the effectiveness of double
data entry to enhance the quality of clinical trials data entered into the
computer from case report forms. Although double data entry is widely used
, no definitive agreement has been reached as to how to model and quantify
the time/cost involved to perform double data entry and the exact gain in d
ata quality derived from its use.
In this paper, an alternative to the verification step of double data entry
is described. This alternative procedure involves the verification of a sa
mple of records from the data set created from the single entry of the data
into the computer. The sampling procedure used for this alternative proced
ure is known in the statistical quality control literature as a continuous
sampling plan. This type of secondary check of the data has the following a
dvantages: (1) it is easily performed by data entry personnel, (2) the cost
/time necessary to perform the check along with the gain in quality of the
data set can be computed, and (3) the sampling plan can be constructed to a
ttain data quality goals set by the data management staff. Examples of how
to select the parameters for this type of data quality assurance procedure
are given in the paper. Control Clin Trials 2000;21:94-102 (C) Elsevier Sci
ence Inc. 2000.