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VOLUME 8 NUMBER 4 • NOVEMBER 2011
ACHIEVING BEST PRACTICE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
Table 1.
Key appraisal criteria used to evaluate PRO instruments
Questionnaire property
Specific criteria
Explanation
Development methods
Patient interviews in population
Were exploratory interviews carried out in the patient population during the
development of the instrument?
Evidence of comprehension in
Were comprehension tests carried out in the population during the development
patient population
of the instrument?
Content validity
Specificity of items for measuring
Do the items ask specific or general questions? Are the items worded in a way that
concept in targeted population
relates to patients’ experience?
Richness of concept coverage
Do all items in the questionnaire together cover the concept of interest?
Ability to detect differences over time
Does the questionnaire appear to be sensitive to changes over time given its wording?
Appropriateness of recall period
Is the recall period suitable for the study design?
Standard credibility
Populations in which used
Is the questionnaire used in the targeted population?
Specific application in which used
Is the questionnaire used in similar programmes?
Psychometric properties
Construct validity
Is there any evidence that the internal structure is consistent?
Reliability: internal consistency
Are the various items of the score non-redundant?
Reliability: test-retest
Do two independent evaluations by the same patient give the same results?
Sensitivity to change: responsiveness
Is the score able to detect changes over time?
Assessing diabetes lifestyle programmes from a
patient perspective
To successfully assess the outcomes of lifestyle intervention pro-
grammes from a patient perspective, relevant key patient outcomes
most attributable to the programme must first be identified, fol-
lowed by a critical review of PRO instruments that would best allow
their measurement.
Key patient outcomes should be identified with careful consider-
ation of the programme-based theory, the programme objectives,
the expected outcomes perceptible by patients, and the target
population.
The identification and selection of PRO instruments should then
follow a structured approach:
• identification of PRO instruments from a literature review and
consultation with experts
• development of appraisal criteria from published documents on
the development and validation of health status measures
10,11
and with expert psychometric advice
• critical appraisal of the identified instruments for relevance,
content validity and credibility of quantitative and qualitative
methods used for its development and validation. The key
appraisal criteria are summarised in Table 1.
Question 1: What are the relevant outcomes of
diabetes lifestyle programmes from a patient
perspective?
For diabetes lifestyle-modification programmes based on empirically
supported theoretical models such as Prochaska’s transtheoretical
model of behaviour change,
12
the behavioural change theory should
drive the hypotheses to test for programme evaluation. Prochaska and
DiClemente suggest that behavioural change occurs in five distinct
stages (precontemplation, contemplation, preparation, action and
maintenance) and that movement through these stages is a cyclical
or spiral process that involves both progress and periodic relapse.
The stabilisation of behaviour change and the avoidance of relapse
are characteristic of long-term maintenance of lifestyle behaviour
change.
Such transtheoretical model-based lifestyle interventions in dia-
betes aim to:
• prepare and motivate patients for taking an active role in chang-
ing their lifestyle (preparation phase)
• support them in making good choices and positive changes in
their lifestyle (action phase)
• support them in maintaining behaviour change (maintenance
phase). These interventions are generally proposed to patients
ready to change their lifestyle (patients in the preparation or
action phases).
In this context, the key patient-relevant outcomes identified as
most predictive of such programme success and sustained behav-
iour change are psychological adjustment to diabetes, motivation
to change and self-efficacy.
Psychological adjustment
is the mental response of a person to a
dreadful life situation. This concept covers the cognitive and behav-
ioural strategies patients may use to deal with and manage their
disease.
13
A positive change on psychological adjustment to diabe-
tes is expected as a result of lifestyle-modification programmes.
Motivation
is the psychological feature that stimulates a person
to action toward a desired goal. Motivation plays an important
role in successful behavioural change
12
and is thus identified as a
key concept to evaluate the benefit of a lifestyle programme on
patients.
Self-efficacy
is a person’s perception of their ability to plan and
take action to reach a particular goal.
14
Self-efficacy was identi-
fied as a key concept in order to document and monitor patients’
perceptions of their ability to plan and take action to reach their
goals, in this case, eating a healthy diet and increasing physical
activities.
Question 2: What are the most appropriate PRO
instruments to assess lifestyle programmes in type 2
diabetes?
PRO instruments were identified using ProQolid and published lit-
erature reviews.
15,16
The search was supplemented with instruments
recommended by clinical and PRO experts.
