Description

The Quality of Life Index (QLI-70) is a multidimensional 70-item self-report questionnaire developed to assess quality of life across different populations.

The instrument approaches quality of life as a broad and multidimensional construct rather than focusing exclusively on physical health. It covers physical, psychological, social, and environmental aspects of an individual’s life, providing a comprehensive perspective on perceived well-being and everyday functioning.

Its multidimensional structure allows researchers and healthcare professionals to examine both overall quality of life and specific areas that may contribute to an individual’s well-being.

Objective

The primary objective of the QLI-70 is to provide an overall assessment of an individual’s quality of life.

According to the source document, the instrument can be used to evaluate the impact of health conditions, treatments, and social factors on everyday life.

It can also be applied in research and clinical contexts to compare quality-of-life outcomes across different population groups.

Dimensions

The QLI-70 covers four broad dimensions of quality of life:

Physical Health: Addresses physical aspects of health, functioning, and well-being.

Psychological Well-Being: Examines psychological and emotional aspects of quality of life.

Social Relationships: Assesses the social dimension of an individual’s life and relationships with others.

Environment: Addresses environmental factors that may influence everyday life and overall quality of life.

Assessment of these individual dimensions can provide a more detailed understanding of the areas in which quality of life is relatively higher or lower.

Scoring

Each QLI-70 item is answered using a Likert-type response scale. The source provides the example of a 5-point scale ranging from:

1 = Not at all satisfied
to
5 = Completely satisfied.

Scores are calculated for the individual subscales of physical health, psychological well-being, social relationships, and environment, as well as for an overall quality-of-life index.

Higher scores indicate better quality of life.

The source document does not provide a detailed scoring algorithm, total score range, reverse-scored items, or specific interpretation thresholds. Therefore, these aspects should follow the scoring instructions associated with the particular version of the instrument being administered.

Validity

According to the available source, studies have supported the instrument’s content validity, construct validity, and criterion validity.

The document also states that the instrument has been translated and adapted into different languages, including culturally adapted versions.

When the QLI-70 is applied to a new linguistic, cultural, or population context, evaluation of its validity within that specific population may therefore be appropriate.

Reliability

The available source reports high internal consistency, with Cronbach’s alpha values greater than 0.80 for most subscales.

The document also states that test-retest reliability has been satisfactory across different populations.

These indicators support the consistency and stability of the measurements obtained from the instrument as described in the available material.

Statistical Analysis and Data Use

QLI-70 data can be analyzed at both the individual subscale level and the overall quality-of-life level.

Descriptive statistical methods can be used to summarize quality-of-life scores within a population.

According to the source document, factor analysis can be applied to examine the structure of the instrument, while comparative statistical methods such as independent or paired t-tests and analysis of variance (ANOVA) may be used, where appropriate to the study design, to investigate differences between groups or assessment periods.

The instrument may also be incorporated into clinical studies to evaluate therapeutic interventions and into epidemiological studies for comparisons across different population groups.

Applications

The QLI-70 can be used in clinical and epidemiological research concerned with quality of life.

In clinical studies, it may be used to assess quality-of-life outcomes associated with therapeutic interventions. In epidemiological research, it may support comparative analyses between different population groups.

Its multidimensional approach enables the simultaneous consideration of physical, psychological, social, and environmental aspects of life, providing a broader assessment than measures focused on a single dimension of health or functioning.

References

Ferrans CE, Powers MJ. Psychometric assessment of the Quality of Life Index. Research in Nursing & Health. 1992;15(1):29-38.

Ferrans CE. Development of a conceptual model of quality of life. Scholarly Inquiry for Nursing Practice. 1996;10(3):293-304.

Skevington SM, Lotfy M, O’Connell KA. The World Health Organization’s WHOQOL-BREF quality of life assessment: Psychometric properties and results of the international field trial. Quality of Life Research. 2004;13:299-310.