The SF-36, a multi-purpose, short-form health survey with only 36 questions could be tweaked to gather the PROM data in different sub-contexts [4]. This instrument yields an 8-scale profile of functional health and well-being scores as well as psychometrically based physical and mental health summary measures and a preference-based health utility index. 

The SF 36 questionnaire has items grouped in 8 domains and a single question on change in health during preceding year. Domains measured are:

• Physical Functioning-10 items
• Social Functioning-2 items
• Physical Role limitations-4 items
• Emotional role limitation-3 items
• Mental health-5 items
• Energy / Vitality-4 items
• Bodily Pain-2 items
• General Health Perception- 5 items

All questions are scored on a scale from 0 to 100, with 100 representing the highest level of functioning possible. Aggregate scores could be compiled as a percentage of the total points possible, using the scoring table. For more information, kindly see Tables 1 and 2 given below.

The scores from those questions that address each specific area of functional health status will be then averaged together, for a final score within each of the 8 dimensions measured. (e.g. pain, physical functioning etc.) For example, to measure the patients energy/fatigue level, add the scores from questions 9a, 9e, 9g and 9i. If a patient circled 4 on 9a, 3 on 9e, 3 on 9g and left 9i blank, use table 1 to score them.

An answer of 4 to 9a is scored as 40, 3 to 9e is scored as 60, and 3 to 9g is scored as 40.9i is omitted. The score for this block is 40+60+40 =140. Now we divide by the 3 answered questions to get a total of 46.7. Since a score of 100 represents high energy with no fatigue, the lower score of 46.7% suggests the patient is experiencing a loss of energy and is experiencing some fatigue. All 8 categories are scored in the same way. Using this questionnaire at the beginning and during the course of care, we can track the progress of the 8 parameters.

The preferred method would be computerized (website) questionnaire administration, where the items are presented on the computer. Others option would be:

• Face-to-face questionnaire administration, where an interviewer presents the items orally.
• Paper-and-pencil questionnaire administration, where the items are presented on paper.

Patients will be asked to self-complete the questionnaires without assistance. Evidence suggests that interviewer-administered questionnaires are associated with a range of response biases and so should not be employed. Similarly, the ad hoc translation of the questionnaires by, for example, local translators, relatives is not acceptable for technical reasons. 

The PROMs used to collect data from patients will comprise a condition-specific instrument and/or a generic instrument, in addition to more general patient-specific information. The patient-specific questions comprise socio-demographic questions and questions about the patient’s general health, previous surgery for the target condition, co-morbidities and length of time with the condition. 

Medical records review for lab and radiology reports could be used to estimate clinical outcome and measures. When it comes to the types of outcome measurements, the data would be in two sets. The first set of data could be taken from the clinician perspective about patient and the treatment provided. This data would be obtained from secondary data sources – medical records of the same group of patients. Then, patients could be interviewed for the second set of data – patient reported outcomes. From the group of patients, selected by using the sampling plans and procedures, the data pertaining to the study variables i.e., related to the treatment received, socio-economic, physiological, psychological could be collected and tabulated. 

The SF 36 is a generic measure, as opposed to one that targets a specific age, disease, or treatment group. Accordingly, the SF-36 has proven useful in surveys of general and specific populations, comparing the relative burden of diseases, and in differentiating the health benefits produced by a wide range of different treatments.

Previous Studies 

Thirty-nine studies were identified supporting the use of the SF-36 with patients undergoing elective coronary procedures; of these, eight studies were carried out in the UK [5-9]. Thirty studies examined outcomes in CABG patients, 13 were concerned with outcomes of PCI; four studies examined both CABG and PCI. 

About half of the studies were published in the last five years. Internal consistency reliability of the SF-36 was supported with Cronbach’s alpha ranging from 0.73 (GH) to 0.90 (PF) in a large study of patients undergoing CABG and/or valve surgery [10]. Similar values were found in a study comparing generic and specific measures for measuring HRQoL after PCI [11]. Cronbach’s alpha exceeded 0.85 for all subscales in a study comparing outcomes following coronary stenting versus balloon angioplasty [12], ranged 0.80- 0.94 in the Stent-PAMI trial [11], and exceeded 0.80 in a postal survey assessing QoL in women after either an acute cardiac event or CABG [13]. Good internal consistency was also reported in a study examining differences in recovery outcomes for two groups of older adults undergoing Cardiac Rehabilitation (CR) post-CABG [14], with high alpha coefficients of 0.84 (pre-test) and 0.81 (post-test) for the PCS, and 0.86 (pre-test) and 0.84 (post-test) for the MCS. High Cronbach’s alpha values in six of the domains (0.82 and above) were reported in a postal survey of post-CABG patients undergoing CR [15]. The PF subscale correlated strongly with the CCS classification in the 1997 study by [12], supporting construct validity of the measure. Construct validity of the SF-36 was further supported by strong correlation of the PCS (0.65) with the EQ-VAS in a study of long-term survival post-CABG [16]; however, correlation between the MCS and the EQ-VAS was weaker (0.48) [16-19].

Table 1: SF-36 Scoring method.