Epidemiology & Technology

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Stata Code for generating corneal opacity outcomes from RAAB 6 surveys

grayscale photography of person's eye
Corneal Opacity Related Outcomes There are four sets of variables Stata Code The above Stata code can be used by anyone under a CC-BY-SA license.

Stata Graph Colors

graphs
Install the packages contributed by Ben Jann: here and here in the Stata Journal. Initialize and set the preferred graph schemes. Here I am setting plain background with dotted grid and legend without any box at 2 o-clock inside graph region. Detailed help for grstyle is there. Assigning Colors Examples

95% Confidence Intervals of categorical outcome by categories of a Risk Factor in Survey Data

data outputs
Use the following program to generate the summary 95% confidence intervals Usage RESULTS You get the N for each category of race, and the Percent and 95% CI for each category of BMI. The First row depicts the order of the results

Easy Estimates Table after Logistic Regression

Regression Models
We need to address several concerns when running logistic regression in Stata. For such situation, the fantastic esttab and estout packages are incredibly useful. An example follows One thing to note, the Variables are not displayed, only their categories. It may prove to be problematic if many variables use same

RAAB6 Surveys Stata Commands for Cataract Surgical Outcomes

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The WHO Eye Care Indicator Menu has prescribed many core indicators. The Core Indicator 6 is Cataract surgical outcome (visual acuity) in the domain of Output – Eye Care Service Quality Definition: Percentage of eyes with: Estimation of these indicators can be accomplished using the below Stata code I have

Stata Code for eCSC and CSC calculations

WHO has identified WHO Effective Cataract Surgical Coverage (eCSC) as a key indicator for monitring Universal Eye Health. LINK There is a slight change from the prior formulae used for eCSC in papers by Ramke et al and the one published by Keel et al. Further, the original CSC estimation

Match string for patterns

One can use Regular Expressions (RegEx) in Stata functions when working with string data Finding whether a String matches a Pattern One can use the ustrregexm function. You can remember it as an abbreviation for "Unicode String Regular Expression Match" = UStrRegExM The above function will be TRUE if the

Using the results of Stata Direct Standardization for display, HTML, putExcel etc

The dstdize command saves certain matrices and scalars. these can be used to access the results and programmatically write them to docx, excel, html files etc Example Usage

Age-Sex Direct Standardization in Stata

When using person level / individual level data (not aggregated data), quick reference commands are: Age standardization within sex proportion msvi, stdize(ageGrp) stdweight(per) over(sex) per = percent of population in age group calculated separately for males and femalesdstdize msvi p ageGrp if sex==1, by(sex) using(stdPop) print AND dstdize msvi p

Tests for Trends in Repeated Cross Sectional Surveys

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The Cochran-Armitage trend test can be used to assess time trends in prevalence of outcomes across repeated cross-sectional surveys. Sample size Calculation in Stata Statistics > Power and Sample Size > Outcome > Binary > Linear Trend in proportions in Jx2 table OR power trend Examples follow Sample size for