12-Item Short Form Survey flow

Introduction

The SF-12 questionnaire (Short Form 12) is a general health questionnaire that allows statements to be made about the patient's state of health over 8 different dimensions. It is the short form of the Short Form 36 questionnaire (SF-36). Some patients have complained that completing 36 questions is cumbersome. Consequently, the originators of the SF-36 developed the SF-12 [1]. Using regression analysis, Ware et al [1] were able to select 12 questions from the SF-36 that reliably produced scores that mirrored those from the SF-36.

The 12-Item Short Form Survey flow contains the 12-Item Short Form Survey (SF12) questionnaire and associated calculation. After form submission, the 12-Item Short Form Survey calculation is executed automatically. It's easy to extend this flow with conditional logic based on the interpretation of the 12-Item Short Form Survey calculation.

12-Item Short Form Survey (SF12) questionnaire

Questions and Scoring

The SF-12 consists of 12 items split over 8 different dimensions. The items cover:

• General health perceptions
• Physical functioning
• Role physical
• Bodily pain
• Vitality
• Social functioning
• Role emotional

Mental health - 2 items;

Calculations

First the raw score is calculated for each dimension by adding each item score within the dimension. Next the raw score is transformed to a 0-100 scale, as follows:

Transformed scale = {(Actual raw score - lowest possible raw score)/Possible raw score range}*100

This transforms the lowest possible score to 0 and the highest to 100. Scores in between are % of the possible achieved score.

Interpretation

Generally, highest scores indicate better outcome and lowest worse.

References

[1] Ware J Jr, Kosinski M, Keller SD. A 12-Item Short-Form Health Survey: construction of scales and preliminary tests of reliability and validity. Med Care. 1996;34(3):220-233. doi:10.1097/00005650-199603000-00003