<http://www.talkstats.com/threads/determining-best-analysis-method-for-health-knowledge-research.17253/>
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"Hi,\r\n\r\nI have data from a dozen countries capturing knowledge on health-related issues.  The same survey, translated appropriately, was used in all countries.  After the initial survey, a training was executed in each country, teaching people about the issues addressed in the survey.  \r\n\r\nNow, we would like to do a post-survey to see if there has been an improvement in knowledge and to compare pre/post change in knowledge between countries.  Within countries, we'd also like to compare the change in knowledge on some demographic variables like gender and age.  For the post-survey, some less relevant questions would be cut from the original survey but the wording of those questions that remain would be the same as in the pre-survey. \r\n\r\nThe problem is that the time between the training and the post-survey would vary.  That is, it has been 2-3 years since the training in some countries, while in others it has only been 6 months.  We would like to conduct the post-survey on the same date for all countries.  \r\n\r\nGiven this information, here are some questions:\r\n\r\n- What is the best statistical analysis for analyzing the pre/post data?  Initial sleuthing leads me to a multi-factor ANOVA as the best choice (allowing us to control for within country factors like gender and age and analyze between countries), but I'd like to hear the opinions of you stats experts.  \r\n\r\n- Is it possible to simply control for the amount of time between the training and post-survey between countries to account for these time differences statistically?  Or is it just not feasible?  Clearly, other factors could influence health knowledge beyond the training as the amount of time since the training increases. \r\n\r\n- If the training is rendered irrelevant because of the differences in time periods between countries, could pre/post results still be analyzed (there would still be a difference in time period between the pre and post surveys between countries)?\r\n\r\n- We would like to rank order the countries with the greatest change in knowledge to the least.  Could this be done statistically?  If so, what method should be used?\r\n\r\nThanks in advance for your help--"
<http://www.talkstats.com/threads/determining-best-analysis-method-for-health-knowledge-research.17253/>