The survey estimate from the four special questions included hours lost due to the respondent's own flu-related illness, care for others, and any flu-related medical appointments.
If a key characteristic in a register would be available that is strongly related to the target variables in the survey, the estimates from the survey could be compared with the register information and included in weighing models in order to adjust for the non-response bias.
The United States Geological Survey estimates that the production increased from 38,700 tonnes in 2005 to 44,500 tonnes in 2006.
The geological survey compiled estimates from a variety of sources, including government and privately held data, from Denmark, Greenland, Norway, Russia, the United States and Canada.
Because participation in the survey was voluntary, estimates from the survey could be biased if responding sample members differ from the state's VR population as a whole.
Most data on the poorest countries is pieced together from surveys, estimates and government figures.
Average OOPE for inpatient care during the 1 year prior to the survey was estimated from questionnaire responses for AP and MH from the baseline and follow-up data.
For that reason, and in the absence of earlier start-up data, the costs of the survey were estimated from project accounts and included as a start-up cost for the project.
Sampling error, with the potential to affect the accuracy of the results of this survey, was estimated from the standard error of variables, which were computed taking the cluster sampling technique into account.
Analyses of the 23 July 1997 storm and flood are based on rainfall and discharge observations from dense networks of rain gages and stream gages maintained by the U.S. Geological Survey and rainfall estimates from two WSR-88D weather radars, both located approximately 150 km from the urban core of Charlotte.
