A likely reason for this may be incomplete reporting of cases in developing countries.
On the other hand, underestimation is also possible, for example, because of physicians' lack of awareness or incomplete reporting of patient medication uses.
Sorry about the very incomplete reporting.
In the state, serious crimes were down 6 percent, but those figures reflected incomplete reporting from New York City for the 11 months.
The extent to which the magnitude and implications of incomplete reporting varies by disease has been reported elsewhere (25).
This often results in redundant data entry, data integrity problems, and inefficient or incomplete reporting.
Other possible factors are mismatched tax records, incomplete reporting of taxable earnings by businesses and misleading answers to the survey.
The criticism about incomplete reporting is aimed at improving the modern surveillance system that was pioneered by the United States.
In addition, the evaluation of many studies is made difficult by poor descriptions of study design and the incomplete reporting of clinical data.
Poor descriptions of study design and incomplete reporting of clinical data have hindered evaluation of many of the reported findings.