2.4 Health Status of Stroke Caregivers
2.4.2.1 The Short-Form Health Survey (SF-36) and Short- Form Health Survey (SF-12)
- The SF-36 has been widely used to measure health status of individuals in general (McHorney et al., 1993), caregivers (Hughes et al., 1999), and individuals with some specific forms of disease, such as stroke (Godwin et al., 2013).
Because the SF-36 was originally constructed to survey health status in populations aged 14 and older (Ware & Sherbourne, 1992). It can be appropriately applied to various age groups. The SF-36 consists of one multi-item scale. Items are organized into eight dimensions or subscales; physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional, and mental health. Details of the items measuring the eight concepts as follows:
(a) Physical functioning. This health concept is measured by 10 items. A three-point Liker scale, ranging from 1 to 3 is used for response – 1 = yes, limited a lot, 2 = yes, limited a little, 3 = no, not limited at all. The score ranges from 0 to 100. High scores mean one is able to perform all kinds of physical activities including vigorous activities without any health limitations.
(b) Role physical. The role limited due to the physical health.
It consists of 4 items. The response categories are 1 = yes, and 2 = no. Scores range
from 0 to 100. High scores mean no limitations of daily activities due to physical health during the past four weeks.
(c) Bodily pain. This consists of 2 items. The first is “How much bodily pain have you had during the past four weeks?” The response categories are 1 = none, 2 = vary mild, 3 = mild, 4 = moderate, 5 = severe, 6 = very severe. The second is “During the past four weeks, how much did pain interfere with your normal work (including both work outside the home and housework)?” The response categories are 1 = not at all, 2 = a little bit, 3 = moderately, 4 = quite a bit, and 5 = extremely. Scores from the two items range from 0 to 100. High scores mean more pain or limitation during the past four weeks.
(d) General health. This scale consists of 5 items. A sample question is “In general, would you say your health is?” Five responses are 1 = excellent, 2 = very good, 3 = good, 4 =fair, and 5 = poor. Another question asks “I seem to get sick a little easier than other people”. The response categories are 1 = definitely true, 2 = mostly true, 3 = don‟t know, 4 = mostly false, and 5 = definitely false. The score ranges from 0 to 100. High scores mean believing that one‟s personal health is excellent.
(e) Vitality. This concept focuses on an individual‟s level of energy and fatigue. It consists of 4 items. An example includes “How much of the time during the past four weeks did you feel tired?” Six responses in Likert format are 1 = all of the time, 2 = most of the time, 3 = a good bit of the time, 4 = some of the time, 5 = a little of the time, and 6 = none of the time. The score ranges from 0 to 100. A high score indicates feeling full of pep and energy during the past four weeks.
(f) Social functioning. This is comprised of 2 items. The first asks “During the past four weeks, to what extent has your physical health or emotional problems interfered with your normal social activities with family, friends, neighbors, or groups?” The responses follow a Likert scale, in which 1 = not at all, 2 = slightly, 3
= moderately, 4 = quite a bit, and 5 = extremely. The second is “During the past four weeks, how much of the time has your physical health or emotional problems interfered with your social activities (like visiting friends, relatives, etc.)?” The responses are 1 = all of the time, 2 = most of the time, 3 = some of the time, 4 = a little
of the time, and 5 = none of the time. Scores from both items range from 0 to 100.
High scores mean one is able to perform normal social activities without any difficulty due to physical health or emotional problems.
(g) Role emotional. It consists of 3 items. A sample question asks “During the past four weeks, (as a result of emotional problems) have you cut down on the amount of time you spent on work or other activities?” The response categories are 1 = yes, and 2 = no. The score ranges from 0 to 100. High scores mean no limitations of daily activities due to emotional health during the past four weeks.
(h) Mental health. The psychological well-being sub-scale is composed of 5 items. A sample question asks “How much of the time during the past four weeks have you been a very nervous person?” The response categories are 1 = all of the time, 2 = most of the time, 3 = a good bit of the time, 4 = some of the time, 5 = a little of the time, and 6 = none of the time. The score ranges from 0 to 100. High scores mean respondents have felt peaceful, happy, and calm during the past four weeks.
(i) Change in health. This consists of 1 item asking about general health now compared to last year. The question in that item is “Compared to one year ago, how would you rate your health in general now?” The response ranges from 1 to 5, in which 1 = much better, 2 = somewhat better, 3 = about the same, 4 = somewhat worse, and 5 = much worse.
In addition, a physical component summary (PCS) and mental component summary (MCS) can be derived from the scale items. Standardized population data for several countries are available for the SF-36 (McDowell, 2006).
The component scores have also been standardized with a mean of 50 and standard deviation of 10 (Finch et al., 2002). Each item is score on a five rating scale. The SF- 36 is scored so that a high score indicates better health.
- The SF-12 was developed from the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) to measure the physical component summary and mental component summary scales in the general US population (Ware, Kosinski, & Keller, 1996). It consisted of 12 items and has two domains as physical and mental. Each item is score on a five rating scale. The SF-12 is scored so that a high score indicates better health.