228662 Challenges in Assessing Dimensions of Functional Status - A Comparison of SIP and SF-12 Instruments

Wednesday, November 10, 2010 : 9:30 AM - 9:50 AM

Carla Fry, MSN, RN , Workplace: Jacksonville University College of Nursing. School: University of Florida College of Nursing PhD Program., Saint Johns, FL
        
Background: Challenges in assessing dimensions of functional status with instruments such as the Sickness Impact Profile (SIP) and the SF-12 has been well documented in the literature. The SIP consists of 136 questions in 12 categories and takes participants approximately 20 minutes to complete. The SF-12 consists of 12 questions and takes only 5 minutes to complete, but has no formal functional status subscale. Two subscales in the SF-12 conceptually represent both physical and emotional aspects of function, and could reasonably be combined for a composite measure (SF-12FUNCT). Problems with the SIP traditional scoring method (SIPv1) have been highlighted in the literature, with a recommended revised scoring approach (SIPv2). Given these challenges, additional research to succinctly capture functional status is needed.

Methods: Using Stata SE 11.0, we compared the relationship between the SIPv1 to the more recently recommended SIPv2. Additionally, a composite SF-12FUNCT score of Role Physical (RP) and Role Emotional (RE) subscales were compared with the SIPv1 and SIPv2, and with other health-related variables of interest.

Results: The SIPv1 and SIPv2 versions were highly correlated (r = 0.99, p<0.001), and did not appear to measure unique or different aspects of functional status. The composite SF-12FUNCT was only moderately correlated with either measure of the SIP, but slightly higher with SIPv2 (r= -0.37, p<0.001). Relationships between other health-related measures such as depression (r= -0.56, p<0.001), total symptoms (r= -0.45, p<0.001), and number of chronic health conditions (r= -0.42, p<0.001) were more robust using the SF12FUNCT.

Conclusions: Available measures of functional status all have significant limitations as outlined in the literature. While not a documented measure of functional status based on SF-12 development, the composite SF-12 is theoretically consistent with a general measure of functional status, appears to correlate more highly with other health measures of interest, and may be a reasonable alternative. Additional methodological research is needed to assess correlations between SIPv1 with SIPv2 scoring, and further validity and reliability testing of the SF-12FUNCT in other study populations.

Learning Areas:
Public health or related nursing
Public health or related research

Learning Objectives:
Upon completion of this presentation, attendees will be able to describe the basic components of the SIP and SF-12 instruments including their challenges, limitations, and correlations found when the instruments were compared to one another.

Keywords: Community Research, Public Health Research

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am an MSN prepared Assistant Professor of Nursing working on the completion of a PhD program. I am involved in research related to the use of functional status instruments.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

Back to: 5083.0: Theoretical/Methodological Issues in Population-Focused Nursing Research