Introduction
Methods
Search strategy and inclusion criteria for articles
Assessment of item content relevance
-
Code for meaning, rather than the exact words
-
When an item asks about ‘satisfaction with X,’ code X rather than emotional wellbeing (‘satisfaction’)
-
When items are subdivided by domains in the original instrument, do not automatically code items as the given domain
-
When the instrument instructions say to consider an item in a certain context, also consider that context when coding
-
Code ‘global quality of life’ when an item refers to life as a whole or when it can be understood in terms of any of the eight domains
Assessment of instrument properties
Properties | Description |
---|---|
1. Target population | A QOL instrument should describe the population it is intended for |
2. Conceptual and measurement model | A QOL instrument should describe (i) the conceptual model including how the authors define the concept of QOL or the theoretical framework within which the tool is developed, and (ii) the measurement model including evidence for the dimensionality of the measure |
3. Instrument development methodology | |
4–6. Mode of administration, number of items and domains, and completion time | A QOL instrument should have low respondent and administrator burden. We examine the mode of administration, the number of items and domains, and completion time |
7. Interpretability of scores | The scores of a QOL instrument should be easy to interpret: (i) there should be information on what high and low scores represent, and (ii) norm values should be available |
8. Available languages | We report the availability of instruments in different languages |
9–11. Responsiveness; Reliability; Construct and content validity | Instruments should have evidence of good responsiveness, internal consistency reliability, construct validity (e.g., convergent and discriminant validity), and content validity in the target population of the research application (here: opioid-dependent people) |
Properties | Score | Assessment criteria |
---|---|---|
Conceptual and measurement model | 2 | The conceptual model is described AND evidence is available on the instrument’s dimensionality |
1 | The conceptual model is described OR evidence is available on the instrument’s dimensionality | |
0 | No information found | |
Instrument development methodology | 2 | The target population was involved in the item generation AND the instrument was pilot tested |
1 | The target population was involved in the item generation OR the instrument was pilot tested | |
0 | No information found | |
Interpretability of scores | 2 | Information on what high and low scores represent AND normative values are available |
1 | Information on what high and low scores represent OR normative values are available | |
0 | No information found | |
Responsivenessb
| 2 | At least moderate effect sizes: SRMa ES ≥ 0.50; Cohen’s d ≥ 0.50; Glass’ Δ ≥ 0.50 |
1 | Below moderate effect sizes: SRM ES < 0.50; Cohen’s d < 0.50; Glass’ Δ < 0.50 | |
0 | No information found | |
Reliabilityb
| 2 | At or above the minimum acceptable value for internal consistency: Cronbach’s α ≥ .70 |
1 | Below the minimum acceptable value for internal consistency: Cronbach’s α < .70 | |
0 | No information found | |
Validity | 2 | Construct validity AND content validity is reported |
1 | Construct validity OR content validity is reported | |
0 | No information found |
Results
Identified instruments
Instrument abbreviation (number of articles the instrument was used in) | Instrument and reference |
---|---|
1. WHOQOL-BREF (n = 57)a
| World Health Organization Quality of Life Assessment-Brief Version [10] |
2. LQoLP-modified (n = 10)b
| Lancashire Quality of Life Profile-modified [50] |
3. IDUQOL (n = 4)c
| |
4. SWLS (n = 4)d
| Satisfaction With Life Scale [51] |
5. PWI (n = 4) | Personal Wellbeing Index [52] |
6. MSQOL (n = 3) | Modular System for Quality of Life [53]e
|
7. Q-LES-Q (n = 3)* | Quality of Life Enjoyment and Satisfaction Questionnaire [54] |
8. SQLP (n = 2)* | Subjective Quality of Life Profile [55] |
9. TEAQV (n = 2)* | Tableau d’Evaluation Assistée de la Qualité de Vie [56] |
10. QOLI (n = 1) | |
11. QOLI-BV (n = 1) | |
12. MQOL (n = 1) | |
13. QLQ (n = 1) | Quality of Life Questionnaire [63] |
14. ComQoL-A5 (n = 1)* | Comprehensive Quality of Life Scale—Adult [64] |
15. EBP (n = 1)* | Escala Bienestar Personal [65] |
16. QOL-DA (n = 1)* | Quality of Life Measurement for Drug Addicts [66] |
Item content
Instrument properties
Instrument | Target population | Mode of administration | Number of items and domains | Completion time (minutes) | (Number of) Available languages | Conceptual and measurement model | Instrument development methodology | Interpretability of scores | Responsiveness | Reliability | Construct and content validity |
---|---|---|---|---|---|---|---|---|---|---|---|
1. WHOQOL-BREF | People in need of health care; any clinical group | Questionnaire | 26 items, 4 domains | NRa
| English + 40+
| 2 | 2 | 2 | 1–2b
| 2b
| 1b
|
2. LQoLP-modified | People with mental illness; patients in mental health care settings | Structured interview | 133 itemsg, 10 domains | 45 | Dutch, Flemish | 2 | 2 | 1 | 0 | 0 | 0 |
3. IDUQOL | Injection drug users | Structured interview using titled picture cards depicting life areas and a Likert scale | 21 items, 21 domains | 20 | English, French, Spanish | 2 | 2 | 1 | 0 | 2c
| 1c
|
4. SWLS | General population | Questionnaire | 5 items | NR | English + 32 | 2 | 0 | 2 | 0 | 0 | 0 |
5. PWI | General adult population | Questionnaire | 7 items + 1 optional item, 7 domains + 1 optional domain | NR | English + 27 | 2 | 1 | 2 | 0 | 2d
| 0 |
6. MSQOL | Psychiatric population | Questionnaire | Core module: 48 items, 6 domains + Optional modules: 11 items, 4 domains | NRh
| English + German | 1 | 0 | 1 | 0 | 2e
| 1e
|
7. QOLI | For people with mental disorders or physical illnesses, or to assess community-wide social problems | Questionnaire | 16 items, 16 life areas | 10 | English | 1 | 0 | 2 | 0 | 0 | 0 |
8. QOLI-BV | People with severe mental illness | Structured interview | 74 itemsg, 8 domains | 16 | English, French, Spanish, Danish, Indian | 2 | 1 | 1 | 0 | 2f
| 1f
|
9. MQOL | People with life-threatening or terminal illness | Questionnaire | 16 items, 5 subscales | 15-35 | English + 15 | 2 | 1 | 1 | 0 | 0 | 0 |
10. QLQ | People in psychotherapy | Questionnaire | 10 items | NR | English | 0 | 2 | 1 | 0 | 0 | 0 |