Background: Stroke is a major, chronically disabling neurological disease, which often radically and permanently changes the lives of the patients. The assessment between of Turkish version of quality of life Index –stroke version III in stroke patients has not been validated in Turkey.

Methods: The study consisted of 216 patients with stroke to evaluate acceptability, reliability and validity of the Turkish version Quality of Life Index in stroke patients. The survey included demographic questionnaire and disease information, The Quality of Life –Stroke Version III Index, Barthell Index.

Results: Internal consistency Cronbach alpha for the QLI-Stroke version items was 0.96. There was no significant difference between pre-test and post-test ratings for all four subscale scores and the global score (p>0.05). Test –retest reliability measured was r: 0.72 (p< 0.05). Concurrent validity was examined by correlating QLI-stroke version Index and Barthell Index. The results of correlation coefficient are low to show validity of the scale even though these were statistically significant.

Conclusion: The Turkish version of Quality of Life Index in stroke patients was found to be acceptable, reliable and valid tool for use among stroke patients. It is easy and practical to use for both informants and investigators and acceptable for research and clinical practice.

Stroke, Quality of life, Nurse, Ferrans and powers quality of life, Turkey

Akyol AD (2015) Reliability and Validity of Turkish Version of Quality of Life Index in Stroke Patients. Ann Nurs Pract 2(2): 1026.

WHO: World Health Organization; QOL: Quality Of Life; HRQoL; Health-Related Quality Of Life; Barthell Index (BI)

Stroke, a major public health issue [1], is among the leading causes of adult disability and can often radically and permanently change the lives of its victims [2]. According to the World Health Organization (WHO),stroke can be defined as: ”rapidly developing clinical signs of focal (or global) disturbance of cerebral function, lasting more than 24 hours or leading to death with no apparent cause other than that of vascular origin” [3,4]. In the world, it has been estimated that 5.7 million patients die from causes related to stroke. In Europe, mortality rate is estimated to be 63.5-273.4/100.000,the prevalence of stroke recovery has been estimated at 100-200/100.000. In Turkey, the prevalence of stroke is estimated to be 175/100.000 [5].On average, 20% of the survivors remain in an institution and 80% return home. However, around 50 % of those who return home present very invalidating impairments [6]

. Stroke leads to major significant functional squeal but objective assessment tools often fail to capture the subjective impact of these impairments [6-8].Traditionally, epidemiological stroke studies focused on mortality and recurrence but not on quality of life issues [1]. Quality of life is an important patientcentered outcome after stroke, since stroke can affect not only physical but cognitive, language, emotional and social functioning [7,9].Hence, stroke outcome indicators must also take account of the victim’s quality of life [6].

The concept of the quality of life (QOL) is complex, highly subjective parameter.QOL has been defined as “an individuals’ perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns. It is a broad ranging concept affected in a complex way by the persons’ physical health, psychological state ,level of independence, social relationships, and their relationship to salient features of their environment” [4,10,11]. Health –related quality of life refers to those aspects of quality of life affected by disease [12]. There is a growing consensus that health-related quality of life (HRQoL) is an important healthcare outcome and a key dimension in the assessment of stroke services [1]. Nevertheless, the routine assessment of HRQoL can prove difficult, as completing lengthy questionnaires regularly can be time consuming for the health professional and perceived as burdensome for the person with stroke [2,13,14]. Measures of HRQoL are particularly relevant in stroke when the key aims of rehabilitation are to facilitate adaptation to disability, to prompt social and community integration, and to maximize well-being and quality of life [15]. Therefore, there is a need to have available a valid assessment of HRQoL, so as to reduce the burden of completion of the instrument by the person with stroke [6,10,16,17].

In Turkey, the focus of rehabilitation programs for stroke patients is to optimize functional independence by overcoming activity limitations and same time to educate the patient and the family and thus preventing restrictions in the patient’s ability to participate in the household ,community and the preventing of disablement in the shortest possible time [2,17].Nurses and healthcare team to provide support for stroke victims, to plan appropriate strategies and to evaluate the results of these strategies, they must first be able to assess quality of life [18].The Ferrans &Powers QOL Index-Stroke version showed that good internal consistency and test-retest reliability firstly [19].There is evidence to support the reliability and validity of the English version of the QOL-Index Stroke version in stroke patients. One report on translations or validation of QOL-Index Stroke Version to Turkish language has been reported previously.

It is known that if an instrument is to be used in a different language, it is necessary to demonstrate that its validity and reliability similar to those of the original instrument (Rejeh et al.2012).

The purpose of the study was to establish the psychometric properties including validity, reliability and sensitivity of a Turkish version of quality of life –stroke version III Index in a sample of Turkish stroke patients.

Design and sample

A cross-sectional and methodological design was used in the study. The study was approved by the Nursing Faculty of Ethics Committee. The study was conducted between 2007-2010 in Izmir province in Western Turkey. A sample the study consisted of outpatients attending the Neurology Outpatient Clinic of a University Hospital who had been diagnosed with stroke. Selection criteria were that participants: 1) have a diagnosis of stroke for more than 6 months, 2) be 18 years or older and 3) be able to communicate and complete the questionnaire.

Patients were excluded if they were cognitively impaired or could not understand the intent of the study. The number of items in the scale (n: 36) was taken into consideration in determining the appropriate sample size for the study. The goal for the research sample was determined to be 216 stroke patients which are six times the 36 items on the QLI-stroke version III Index.

Data were collected by the researcher to every Tuesday. This study was done for 48 weeks (two years). The duration of interviews was approximately 20-25 min for each patient.

Instruments

A three-part survey was used to collect the data by researcher.

The survey included 1) Demographic questionnaire and disease information 2) The Quality Of Life –Stroke Version III Index 3) Barthell Index

Demographic questionnaire and disease information: Demographic information sheet covered basic patient information such as age, gender, education, marital status, occupation. Disease information covered patients’ diagnoses, type and year, medications, other chronic disease and habits.

Quality of Life Index-Stroke Version -III: Quality of life was measured using Ferrans and Powers Quality of Life Index-Stroke Version III. The QLI –stroke version has 72 items and is measure composed of two parts: the first part measures satisfaction with various domains of life, and the second part measures the importance of the same domains to the participants .It covers four underlying domains: health and functioning, socioeconomic, psychological and spiritual, and family. The QLI-stroke version items are evaluated on a six –point Likert-type scale in which the categories range from “very satisfied” to very dissatisfied and “very important” to “very unimportant”. The range possible for the overall score is 0 to 30.While higher scores on the scales showing that life quality is high and a lower score show that life quality is low [20,21].

Barthell Index (BI): BI was developed by Mahoney & Barthell in 1965 with to measure functional disability by quantifying patient performance in 10 activities of daily life. These activities can be grouped according to self-care (feeding, grooming, bathing, dressing, bowel and bladder care, and toilet use) and mobility (ambulation, transfers, and stair climbing).BI scores range from 0 to 100 with a maximal score (100) indicating that a patient is fully independent in functioning, and the lowest score (0) representing a totally dependent bed-ridden state.

Validity studies

Translation procedures: Written permission was obtained from Ferrans and Powers to adapt the QLI-Stroke version in stroke patients. The English version of the scale was translated into Turkish by the researcher and 10 nursing faculty members. The scale was translated back from Turkish into English by three language experts. The resulting English text was compared with the original English text and necessary changes were made and the pilot testing was performed with 10 patients.

Content validity: To test clarity and content validity, the translated version was submitted to a panel consisting of ten specialists in the area of knowledge of the instrument, who were informed of the measures and concept involved. The Turkish version of the QLI-Stroke Version was sent to 8 teaching faculty members, one nurse who working in stroke units and one physician for their opinions on content validity. They evaluated every item for its distinctiveness’, understandability and appropriateness for the purpose. The faculty members used an index for evaluation, on which a score ranging from 1 to 4 is given for each item (1: inappropriate, 4: Appropriate) Changes were made in the statements based on their recommendations and the tool took its final form.

Construct validity: The Kaiser –Meiyer-Olkin (KMO) index, which is criterion for determining whether items are appropriate for basic component analysis, was investigating for the exploratory factor analysis (EFA) sample. KMO index was 0.92 for the EFA sample. Barlett’s test was 7780.7, p<0.000.

Internal consistency reliability of the scale: To establish the internal consistency of the instrument, Cronbach alpha coefficient was calculated for the total score of the QLI-stroke version.

Test-retest reliability: Test-retest reliability was evaluated the Pearson product moment correlation coefficient between pretest and posttest with a 25-30 day interval in a sample of 30 patients. In determining the internal consistency Spearman –Brown and Gutmann split –half reliability coefficients were calculated. To determine whether or not there were differences in the mean scores obtained from scale and subscales between the first and second administration, the scale was evaluated using the t test in dependent groups. No statistically significant differences were found (p> 0.05)

Data collection: Approval for using the scale was received from the author via e-mail. The ethic committee of the Ege University Faculty of Nursing and Ege University Hospital approved the research.

Data collection was conducted through face to face interview with the stroke patients in outpatient clinic by the researcher. The researcher interviewed the patients individually described them the study and obtained informed verbal consent, before administering the questionnaire.

Data analysis: Analysis was conducted using descriptive statistics and appropriate reliability and validity statistical tests using the Statistical Package for the Social Services SPSS 15.0 (SPSS Inc.,Chicago, IL, USA). The reliability and validity of the QLI-Stroke version were evaluated as follows language validity, content validity, construct validity, internal consistency reliability of the scale, test-retest reliability.

Participant characteristics

Demographic and disease-related characteristics of the patients are represented in table 1.A total of 216 patients participated in this study. The mean age of participants was 62.50± 11.89 (SD) years. The majority of participants were men (57.4 %), married (75 %), retired (54.2 %) had graduated from primary school, and had some chronic disease (85.6 %) such as hypertension or diabetes (Table 1).

Table 1: Demographic characteristics of stroke patients.

Internal consistency

Internal consistency was established by calculating the cronbach alpha coefficient. Coefficients of 0.96 for the QLIStroke version items indicate good internal consistency for the QLI-Stroke version in stroke patients. The item total correlation coefficients are represented (Table 2 and 3).

Table 2: Reliability statistics of the subscales the QLI-Stroke Version (n: 216).

Table 3: Item analysis and internal consistency of the QLI-Stroke version.

Test-retest reliability

Test-retest reliability was evaluated the Pearson product moment correlation coefficient and paired t tests between pretestposttest ratings over a 20 to 28 day interval in a subsample of stroke outpatients. There was no significant different between pretest and posttest ratings for all four subscale scores and the global score (p>0.05). The test- retest reliability ranged from 0.61 to 0.72 for the QLI –stroke version III (It covers four underlying domains: Health & Functional Subscale: 0.61, Socio-economic subscale: 0.70, Psychological-Spiritual: 0.63, Family subscale: 0.61, Total QLI: 0.72). Test –retest reliability measured was r: 0.72 (p< 0.05).

Concurrent validity

For concurrent validity between QLI-stroke version Index and Barthell Index for stroke patients was examined correlation analysis. The results of correlation coefficient are low to show validity of the scale even though these were statistically significant (p< 0.05) (Table 4).

Table 4: The results of correlation coefficient between QLI-Stroke version III Index and Barthell Index.

The validation study of the Turkish version of the QLI – stroke version demonstrated the evidence to support reliability and validity of the QLI-Stroke version for measuring quality of life among Turkish stroke patients and is consistent with the psychometrically validated English version in stroke patients.

The calculated KMO was 0.92 indicating that the sample was large enough to perform a satisfactory factor analysis. It has been reported that for KMO when statistical information is between 0.90 and 0.89 it is very good [22]. In the study the KMO was 0.92 which shows that the size of the sample was excellent. A linear direction and low-level correlation was found between total mean score QLI-Stroke version and the mean points of the sub-dimensions and the mean score the Barthell Index. A linear direction and low-level correlation was found between total mean score QLI and the mean score the Barthell Index by Exel et al and Muus et al. In other research, a linear direction and medium-level correlation was found between total mean score QLI and the mean score of ADL [18]. The Newcastle Stroke-Specific Quality of Life Measure (NEWSQOL) domains feelings, communication and cognition low/moderately correlated with Barthell Index scores (–0.49 to –0.28) [23].

The tool cronbach alpha coefficient for the total instrument was 0.96.The alpha coefficient for four domains (health & functional, social &economic, psychological-mentally, family) were 0.93, 0.90, 0.93, 0.87 respectively. In the research by King (1996) the Cronbach alpha coefficient for health & functional was 0.86, social & economic was 0.77, psychological &mentally was 0.83, family was 0.32.In the comparison our study Cronbach alpha values with the original’s Cronbach alpha values, all three subscales had very similar values, the Cronbach alpha coefficients for the family subscales were higher than in King study (1996). The internal consistency was 0.96 in this study. The internal consistency level of the original scale was found to be 0.91. Testretest measurement of the stability of an instrument is the most frequently used analysis of reliability. It is frequently evaluated using Pearson Product Moment Correlation [24]. Correlation coefficient between test–retest scores on instruments should be at least 0.70 [24]. In this study, the stability coefficient between the two administrations of the QLI-stroke version III was found to be 0.72.Therefore, the translated Turkish version of Ferrans and Powers’ Quality of Life Index in Stroke Patients was found to have reliability. The results between the two administrations of the scale were similar.

Statisticians also recommend that the two test results’ score means and standard deviations be examined for similarity [11,24]. When this calculation was done, no statistically significant difference was found in the score means (p > 0.05). In the administration of the same instrument to individuals at different times, the individuals gave similar and consistent responses to items indicating the stability of the instrument [22]. In this study results showed that the QLI-stroke version III is a reliable and stable instrument for assessing quality of life in Turkish stroke patients.