FAQs about Cohort Data Who do I contact ot get access to this module? Please send email to request a username and password for this module. What is the difference between the Cohort Module and the Infant Mortality Module? In the Live Birth/Infant Death Cohort Module the numerator consists of deaths to infants born in 1999 whether the death occurred in 1999 or 2000. As compared to the Infant Mortality module, where the numerator consists of all infant deaths occurring in 1999 that have been linked to their corresponding birth certificates, whether the birth occurred in 1998 or in 1999. The denominator for both files is the 1999 birth file, which contains all South Carolina Resident births occurring in 1999. Why is the live birth cohort module needed? This module allows sers to compare infant deaths to surviving live births and see what the differences are between the two. This allows users to draw conclusion about what the risks factors are for an infant death. Public Health researchers and program developers can then taylor the ir programs to better meet the needs of mothers and children who are at a higher risk of an infant death and prevent these tragic event from occuring. This data compares the infants who died to those who were born in the same year or cohort. This give researchers a better view of what was happening to all births in that year instead of just looking at births that occurred the year the child died. What is the Relative Risk The relative risk is defined as the probability of disease in the exposed group divided by the probability of disease in the unexposed group(1). In this dataset instead of disease the outcome is infant death. What does the relative risk do? The Relative Risk allows users to see the differences between two exposure status and outcomes, and provides a reliable statistic that helps in interpreting these risks How do I calculate Relative Risk? You must chose survival status as the column variable and then click calculate relative risk, an example page with specific instructions and additional details is available by clicking here:(Cohort Relative Risk Calculation Page). What are Confidence Intervals? Confidence intervals are general measures of the rate or risk of an event. They are defined by the risk or rate given and then using the variance or standard error are bands to determined how sure we are of the statistic. With 95% confidence intervals we are 95% confident that the true rate or risk falls between the intervals. The width of the intervals provides a good idea of how stable the statistics is, a small interval between the lower and upper bounds generally means that the statistic is stable with large intervals the statistic is not as reliable and is generally caused by a low number of observations. What does it mean when I get a relative risk less than one? Relative risks and confidence intervals that are less than one imply that the risk category selected is less likely to have an infant death than the non-risk category. To have the statistic be more meaningful switch the risk and non-risk groups in the previous page, then regenerate the statistic. Why can't I get the relative risk button to show up? Survival status must be the column variable, try rotating the table or go to the example page for more information and step by step directions. Why can't I generate Relative Risk with lots of different Cohort Indicators? This is to restrict the user from obtaining bad statistics. By using multiple indicators from several different groupings variables would not be exclusive and would be counted multiple times. This would then allow statistics to be generated that would be false. Why is this page password protected? Due to the large amount of confidential data, this module was built upon the idea that it would primarily be an in-house inter-agency module. How do I get access to this module? Please contact the Division of Biostatistics and Health GIS to obtain a memorandum of agreement. This provides to DHEC the purposes and time length needed for using this application Why are there so many variables? In this module we tried to include as many variables as possible. This allows us to provide a number of different analysis schemes and varying ways of presenting the data. This also allows to better show what variables are significant factors in infant deaths. What does a rate mean? A rate is a comparison of two populations where in the numerator is included in the denominator. In the Cohort module the numerator could be the number of live births, surviving live birth or total live births and the denominator is the total number of livers births. This ratio is then multiplied by 1000 to provide a better interpretation of the result. For an example please the the Animated Formulas page. What is percent by row/column? Percent by row/column is taking the number of observations in the table and dividing them by the total number in the respective row or column. When cohort indicators are chosen the denominator the total number of events that occurred in the years chosen. What is the best way to print the pages? There are numerous ways that users can print the desired pages. For the supporting pages the easiest way is to hold the left click button down on the mouse and scroll over, highlighting, the material that the user wants to print. Then right click on the mouse and choose print. Once the print options page comes up, users should select the selection option in the print range box as to print exactly what was selected. Tables, trendlines, and bar charts have their own printer friendly buttons that can help in printing those pages. If users are using netscape they can use the fit to page which allows users to fit the data to the pages specified. Users could also adjust the layout of the pages printed from portrait to landscape in order to capture the whole document or image. Why doesn't the mapping page map rates less than one? The maps generated take the rate and rounds it up or down according to the rate. Rates above .50 are coded into the 1-4 group and rates less than .50 are coded as a zero. To get the real rates please generate the frequency and rate in the "create a table" page selecting all counties and other characteristics as desired. If the legend on the map has label 1-4 and 4-8 and the frequency or rate is 4.0, which level will this frequency or rate fall into? Frequency or rates equaling the dividing point in the legend fall into the larger of the categories. A frequency or rate of 4.0 will fall into the 4-8 category. Why do I get a N/A sometimes for the rate? This is due to missing denominators in the rate calculation. This will always occur for the unknown category. Other times this will occur when there were no denominator (live births) for the selection chosen, the frequency of the characteristic chosen will always be zero in this case and the rate can be seen as zero. Why do I get N/A sometimes for the 95% confidence intervals? Users will see an N/A for the 95% confidence intervals when the rate is either N/A or equals zero. Who do I contact for more analysis? Please contact the Division of Biostatistics and Health GIS for further information.(803)898-3649