Summary

This method compares a current value against a baseline value and returns the percentage increase or decrease. The item values being compared can exist on different forms scheduled against different study events.

Formal Expression

The following variables may need to be updated based on specific study design naming conventions…

BASELINE_STUDY_EVENT
BASELINE_FORM
BASELINE_ITEM_NAME
THIS_ITEM_NAME

Note also that the number in line 16 can be modified to adjust the decimal place precision of the percentage increase or decrease.

//calculates percent increase or decrease compared to BASELINE_STUDY_EVENT
//adjust the first four variables

var BASELINE_STUDY_EVENT = 'Screening';  //study event name associated with the baseline form
var BASELINE_FORM = "Baseline Form"; //baseline form name
var BASE_ITEM_NAME = 'AverageSys'; //baseline item name to be compared 
var THIS_ITEM_NAME = 'AverageSys'; //the name of the current item
var percent = null;

var baseForms = findFormData(BASELINE_STUDY_EVENT, BASELINE_FORM);              //find the baseline form
    if (baseForms !== null && baseForms.length === 1) {                             //if the form exists perform the following 
        var baselineSum = findFirstItemValueByName(baseForms[0], BASE_ITEM_NAME);   //find the baseline item value
        var thisFormSum = findFirstItemValueByName(formJson, THIS_ITEM_NAME);       //find the value of the current item
        if (!isNaN(baselineSum) && !isNaN(thisFormSum)) {                           //ensure neither value is null
            percent = ((Number(thisFormSum) - Number(baselineSum)) / Number(baselineSum))*100; //perform the calculation... ((current - baseline)/baseline)*100
            var percentTruncate = percent.toFixed(1);                                       //specify decimal place precision
        }
    }

return percentTruncate;

Documentation

Comparison to Baseline

Summary

Formal Expression