Introduction
The World Health Organisation (WHO) defines health as "a state of complete physical, mental, and social well being, not merely the absence of disease or infirmity" (WHO, 1958). As providers of health care attempt to evaluate the effectiveness of interventions aimed at controlling or reducing the sequelae of diseases such as cardiovascular conditions, morbidity and mortality indices are too crude and insensitive. [
1] Measurement of health, the effects of disease and the impact of health care ought to include not only an indication of changes in disease frequency and severity but also an estimate of patients' perception of health status before and after treatment.
Health-related quality of life (HRQL) refers to a multitude of subjective and objective experiences among which health, well-being and the ability to function in day-to-day activities are essential. [
2] HRQL instruments provide a valuable tool to assess the impact of disease, effect of treatment and other variables affecting people's lives. Outcome measures used to evaluate HRQL among cardiac patients have been introduced [
3,
4] and numerous generic and disease-specific questionnaires have been developed but there is no general consensus on their relative merits. [
5,
6]
Population-based studies confirm that the prevalence of coronary artery disease (CAD) is higher among Iranian population even than in western countries; [
7] its high mortality rate [
8] makes CAD the principal cause of death in recent decades [
9] In the absence of an appropriate tool for measuring HRQL in an Iranian population, the MacNew Heart Disease Health-related Quality of Life (MacNew), a disease-specific HRQL instrument, was translated into Farsi and administered to a Farsi (Persian)-speaking population with myocardial infarction (MI). This study aimed to measure HRQL in a group of Iranian patients with CAD and documented MI.
Results
We recruited 51 patients (age range 36–81 years; mean 60 y, SD = 11.7) whose major demographic features are documented in Table
1. Six patients omitted answering one question, equating to a data loss of less than 1%. Although responses skewed towards higher scores, 70% of responses covered the entire 7-point range. At the domain-level, one patient scored at the floor on each domain while two patients scored at the ceiling level on both the physical and emotional domains. Median response was 5–7 for 77% of items (20 out of total 26 items), comparable to the original MacNew results. [
11] Younger patients had better physical, social and global but not emotional scores (P ≤ 0.05); no significant difference was found in the emotional domain. Duration of hospital stay, literacy and occupational status did not influence any of the HRQL scores.
Table 1
Patients' characteristics
Gender | Male | 45 (88%) |
| female | 6 (12%)) |
Age | <65 | 32 (63%) |
| >65 | 198 (37%) |
Working status | Working | 29 (59%) |
| Unemployed | 5 (10%) |
| Retired | 15 (31) |
Admission to CCU | First | 33 (72) |
| 2nd
| 7 (15) |
| >2 | 6 (13) |
Education level | Illiterate | 25 (51) |
| Left school @14 | 19 (39) |
| College/university | 5 (10) |
Comorbidity | Yes | 15 (29) |
| No | 36 (71) |
Duration of stay at hospital | ≤ 8 days | 29 (58) |
| >8 days | 21 (42) |
Principal component analysis
Table
2 shows factor weights for each domain at the baseline test with 63% of variation explained. The 'social domain' accounted for 47% of variation and the 'emotional domain' for more than 10% (Table
2). Results in the Farsi version of the MacNew are similar to the contribution of the items to the three different domains in the recommended scoring system [
10] except for three of the 26 items: numbers 3 (confident), 18 (frightened) and 22 (over-protective family). Item number 3 (confident) was statistically allocated to the social domain in the Farsi version rather than to the emotional domain as in the English version [
10]. Item number 18 (frightened) had more relevance statistically to the social and physical domains in the Farsi version, while in the original report it was allocated to the emotional domain. Similarly, item number 22 (over-protective family) was allocated to the social domain while in our Farsi-speaking sample none of the correlation coefficients gained enough significance (>0.40) to contribute to any domain. These minor differences could be explained by the small population sample.
Table 2
MacNew components mean rank in age and sex groups
| Mean rank | Z score | Mean rank | Z score | Mean rank | Z score | Mean rank | Z score |
<65 | 27.7 | -.98 | 29.6 | -2.1* | 30 | -2.3* | 29.3 | -1.9* |
> = 65 | 23.6 | | 20.8 | | 20.2 | | 21.2 | |
Male | 27.2 | -1.7 | 27.7 | -2.2* | 27.3 | -1.7 | 27.5 | -1.9* |
Female | 16.5 | | 13.2 | | 16.3 | | 14.8 | |
Psychometric properties
Table
3 describes the major psychometric results of the Farsi version at baseline and 4-week following discharge after acute myocardial infarction. Baseline domain means were 5, 5.3 and 4.9 for emotional, physical and social domains (at baseline) respectively. The 4-week follow-up clinic was attended by 27 patients as two patients died during the month following discharge and 22 (43%) missed the second visit. No significant differences were detected between follow-up clinic attendees and non-attendees when controlling for age, gender, level of education and duration of hospital stay. There was no significant difference in global score or in any of the three domains (Table
3) among patients with baseline and follow-up assessments (Z value: -0.33 to -1.66, non-significant). The lowest item-level score was higher one month after discharge compared with baseline (Fig. 1). Physical and global scores improved in men with no change in social and emotional scores.
Table 3
Adjusted factor weights in principal component analysis
1. Frustrated |
.600
|
.463
| .171 |
2. Worthless |
.757
|
.546
| .180 |
3. Confident | .451
| .204 |
-.711
|
4. Down in the dumps |
.771
|
.678
| 0 |
5. Relaxed |
.687
|
.797
| -.185 |
6. Worn out |
.724
|
.713
| .140 |
7. personal life |
.592
|
.851
| -.141 |
8. Restless |
.414
|
.726
| 0 |
9. Short of breath |
.545
| -.229 |
.753
|
10. Tearful |
.560
|
.553
| .109 |
11. More dependent |
.722
| -.154 | -.232 |
12. Social activities |
.828
| -.227 | 0 |
13. Others less confidence |
.811
| -.377 | -.103 |
14. Chest pain |
.676
|
.396
|
.554
|
15. Lack self-confidence |
.855
|
.350
| .135 |
16. Aching legs |
.652
| -.125 |
.712
|
17. Sport/exercise limited |
.741
| -.217 |
.545
|
18. Frightened |
.660
| 0 |
.663
|
19. Dizzy/lightheaded | .296 | -.158 |
.367
|
20. Restricted/limited |
.832
| -.170 |
.360
|
21. Unsure about exercise |
.835
| -.344 |
.364
|
22. Overprotective family | -.143 | -.295 |
.239
|
23. Burden on others |
.806
| -.323 | -.196 |
24. Excluded |
.810
| -.379 | -.375 |
25. Unable to socialise |
.900
| .339 | 0 |
26. Physically restricted |
.872
|
.412
|
.391
|
Total variance explained | 47% | 10.2% | 5.8% |
All domains had excellent agreement (Intra-class correlation varied between 0.92–0.95) at p < 0.001 (Table
3). The corrected total-item correlation at baseline ranged from 0.32–0.87 in different domains. Question 22 (over-protected family) was omitted in the analysis of social and global item correlation as an outlier (Spearman rho = 0.07 and 0.17 for social and global scale respectively) and this variable may need to be the subject of modification for the Farsi version of the MacNew. Internal consistency for each domain was supported with Cronbach's alpha = 0.92 for the emotional and physical domains, 0.94 for the social domain, and 0.95 for the Global score. Test-retest analysis in those attending the follow-up clinic showed significant correlations in emotional and physical domains (P ≤ 0.05) and the global scores (P < 0.01). Table (
3)
Discussion
A common critique of quality of life tools in clinical research is that data are 'soft' and less reliable than traditional clinical assessment or physiological measurement. Nevertheless, both generic and disease-specific tools can detect subtle clinical changes quite precisely [
23], especially in cardiac disease.[
24] English language-based quality of life tools have been tested in a wide range of diseases; overall in clinical practice and in health service research, they have proven so useful that both generic and disease-specific tools have been translated into a variety of other languages for wider application.
Coronary disease is at least as prevalent in Iran as in most Western nations but population studies have been restricted by the lack of culturally-sensitive investigational tools in Farsi to assess, inter alia, quality of life. This survey reflects the first administration of such a health-related quality of life questionnaire among Iranian cardiac patients and provides an interesting insight into the quality of life of survivors of a myocardial infarction in this patient group.
Accomplishing the recommended approach to translation to achieve language equivalence was fairly straightforward but administration of the tool revealed several unexpected problems. First, the literacy rate of this population at 50% was considerably lower than the Iranian mean, which made MacNew difficult to administer. Second, this study was a reminder that cultural barriers do exist among populations with strong religious beliefs; for example, questions relating to sexual activity are particularly difficult. Third, self-administered tools are a novel experience for Iranians; as an alternative, training for and conducting interviews is costly and cannot be integrated into routine assessments until validity has been demonstrated in larger samples.
The large variety of generic and disease specific instruments can confuse researchers contemplating the most appropriate tools for quality of life investigation. We thought that the specificity of the MacNew for cardiac patients might be the most appropriate tool to assess HRQL in our patients. Its acceptability and reliability are proven, which favours its application in population studies, and several domains can predict adverse outcome [
3], providing confounders such as disease severity and concurrent medications are taken into account. The latest version of MacNew applied in this study is considerably different from its predecessor and this perhaps explains the unexpectedly improved reproducibility compared with the original application.[
25] As a general rule, however, the combination of generic and disease-specific QOL questionnaires provide complimentary information. [
26‐
28]
We were pleased with the Farsi version of MacNew. There was minimal loss of data, internal consistency exceeded that recommended [
21] and was comparable with previous studies [
10,
11,
13] and, overall, reproducibility was satisfactory. We did observe both similarities and differences between Iranian and Western populations. For example, emotional and physical scores were comparable but our Iranian patient group reported poorer social quality of life.[
10]
Surprisingly, our patients found an interview-administered questionnaire acceptable and this has encouraged us to test MacNew in larger populations, to investigate the feasibility of a self-completed tool, exploring the actual weight of item 22, comparing generic and other specific questionnaires, and specifically to examine the validity of the MacNew (Farsi) by applying a standard cardiovascular classification scale concomitantly. Provided that larger studies confirm that MacNew (Farsi) is acceptable to our patients, we foresee quality of life assessment being widely adopted as an adjuvant to clinical assessment and physiological measurement in routine clinical practice Iran. This approach will facilitate patient management, allow international comparisons and direct medical services to meet patients' needs.
Table 4
Baseline data psychometric analysis
Emotional | 4.99 (1.35) | 5.21 (1) | -0.33 (0.74) | 0.54–0.85 | 0.92 | 0.92 (P < 0.001) | 0.42 (P < 0.05) |
Physical | 5.29 (1.27) | 5.22 (0.99) | -1.66 (0.09) | 0.44–0.84 | 0.92 | 0.92 (P < 0.001) | 0.38 (P < 0.05) |
Social | 4.91 (1.31) | 5.11 (0.98) | -0.47 (0.64) | 0.66–0.87 | 0.94 | 0.93 (P < 0.001) | 031 (P = 0.11) |
Global | 5 (1.26) | 5.18 (0.95) | -0.65 (0.51) | 0.32–0.86 | 0.95 | 0.95 (P < 0.001) | 0.50 (P < 0.01) |
Acknowledgement
Authors are grateful to CCU nursing staff in particular R Bigdelloo BSc, and Research Department in Qazvin Uni. of Med. Sc., specifically S Asefzadeh PhD, and A Javadi MSc., for their efforts in conducting interviews, follow-up and related tasks.
Authors' contribution
MAL, HRJ, MM and DG designed the study, HRJ admitted patients and conducted the interviews, MAL analysed data and wrote the first draft, NBO and DG commented on analysis and discussion and all authors approved the final manuscript.