WHOQOL-100 (World Health Organization Quality of Life 100 item questionnaire)
The WHOQOL-100, Hindi was designed to determine the impact that disease and health intervention has on QOL. One of the initial testing sites was in India at the New Delhi center as part of the WHOQOL project in 1997. The WHOQOL-100-Hindi categorizes 100 items in four dimensions (physical, psychological, social, and environmental health) and 24 facets. Each facet contains four items and is rated on a five-point scale. Also included is one facet examining overall QOL and general perceptions of health (The WHOQOL Group 1998). The WHOQOL-100, Hindi was reported to be qualified for use in health care settings to provide a comprehensive assessment of QOL (Saxena, Chandiramani, and Bhargava 1998).

Strengths: The WHOQOL-Bref has been developed through rigorous methodological development over a number of years for measuring quality of life in India (WHOQOL Group 1993). The main analysis found that data from 15 worldwide centers in developing and western countries supported the notion that some aspects of QOL are universal throughout different cultures (The WHOQOL Group 1999). Statistical analysis of the WHOQOL-100, Hindi questionnaire shows that there are basic factors inherent to quality of life worldwide and that they do not differ substantially across cultures. The WHOQOL-100, Hindi provides an internally reliable and valid method for assessing QOL. The WHOQOL is being expanded to test the universality of the WHOQOL-100, Hindi in other cultures beyond the initial 15 (The WHOQOL Group 1998). This instrument has been translated into Hindi, Tamil, and English (Prabha Chandra, personal communication,23 September, 1999).

Limitations: The data were collected using a cross-sectional design and test-retest reliability in a longitudinal study has yet to be conducted, but this is currently underway. The sensitivity of this measurement is also currently being tested. Until longitudinal studies are conducted to determine further validity of this questionnaire it appears that the major limitation of this instrument is its long length.

WHOQOL-BREF (The WHO Quality of Life Abbreviated Questionnaire)
The WHOQOL-BREF, Hindi was developed to provide a brief version of the WHOQOL-100, Hindi for use in studies needing the practicality of a short questionnaire, in large-scale epidemiological studies, for audit, and clinical work and intervention evaluation (World Health Organization 1997). The WHOQOL-Bref encompasses 24 facets and provides a profile of scores on four dimensions of quality of life: physical health, psychological, social relationships, and environment (The WHOQOL Group 1998). Each facet is rated on a five-point scale. This instrument also provides one global rating on QOL and general health.

Strengths: The WHOQOL-Bref has been developed through rigorous methodological development over a number of years for measuring quality of life in India (WHOQOL Group 1993). The WHOQOL-Bref, Hindi correlated well (at about 0.9) with the WHOQOL-100, Hindi. The WHOQOL-Bref, Hindi may adequately be used in place of the WHOQOL-100, Hindi because it includes items directly from each facet of the WHOQOL-100, Hindi. The WHOQOL-Bref, Hindi provides an aggregate score as well as scores in four quality of life related dimensions. The dimension scores exhibited good content validity, discriminate validity, test-retest reliability, and internal consistency. This instrument should provide a quick, useful alternative to the WHOQOL-100, Hindi where time is a consideration in administration and scoring of the instrument. It also covers a large number of domains that are integral for assessing QOL (WHOQOL Group 1998). The WHOQOL-Bref, Hindi is available in Tamil and is currently being developed for use in the Kannada language as well (Prabha Chandra, personal communication, 23 September, 1999).

Limitations: This instrument does not provide an assessment of the individual facets within the dimensions (Gill & Feinstein 1994; Saxena, Chandiramani, & Bhargava 1998). This instrument is longer than some other measures (i.e., the SF-12).

MOS (Medical Outcomes Study-derived quality of life measures)
Questionnaires developed from the Medical Outcomes Study are the most widely used health status instruments in HIV research (Wu et al. 1997b). These measures include the MOS-HIV, SF-12, SF-20, SF-21, SF-36, SF-38, SF-56, and the HIV Cost and Service Utilization Study (HCSUS). There is also a version called the IQOLA being developed for international use. These questionnaires cover between two and 11 dimensions and utilize between 12 to 56 questions (as per their names). The MOS instruments generally take a short time to complete (< 15 minutes) with sub-scales scored from 0-100. Most of these instruments provide overall scores and often include the separation of physical and mental health scores. In addition, there is extensive credibility for the construct and predictive validity, reliability, and responsiveness of these instruments as these instruments have been administered to over 20,000 patients (Wu et al. 1997a). The most commonly used instruments for HIV research are the MOS-SF-36, MOS-SF-20, and the MOS-HIV.

MOS-SF-36 (Medical Outcomes Study 36 item questionnaire)
This multidimensional tool is the most widely used health status instrument worldwide (Hays & Shapiro 1992; Wood-Dauphinee 1999). This instrument uses a short 36 item questionnaire on eight dimensions: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, general mental health, social functioning, energy/fatigue, and general health perceptions. In addition to this, it provides a single item for perceived change in health. Items are scored and aggregated to provide a scale ranging from 0-100 (0 = poor health and 100 = good health).

Strengths: The SF-36 can be either self-administered or administered by a trained interviewer and takes about 5-10 minutes to complete (Bowling 1997). This questionnaire has high internal consistency and strong psychometric properties (Vanhems et al. 1996). The SF-36 has demonstrated high reliability (Hays & Shapiro 1992). The SF-36 has good responsiveness to change in clinical conditions (Bowling 1997). The results can be machine scored and has been evaluated in large population studies (Kaplan 1998).

Limitations: The sub-scales are not aggregated to give the global score making it more complicated to score. Mean scores are obtained on each sub-scale, which has a tendency to distort the results due to outlying values. The questionnaire has not been developed through extensive consultation with the general population. This questionnaire does not contain age-specific questions and may not be appropriate at each age level (Kaplan 1998). The bodily pain scale has been reported to show low convergent validity with severity of illness and independent pain scores. Furthermore, floor and ceiling effects have been reported for the SF-36 (Bowling 1997).

Global Indices

A VAS
A single item assessment of a patient's global health-related quality of life that uses a scale from 0-100 (worst imaginable health state to best imaginable).

Strengths: Provides a reliable, valid assessment of HRQOL that is easy to complete and has widely been used to assess patient outcomes.

Limitations: It only provides a global rating of HRQOL.

Patient-preference Scales

QWBS (Quality of Well-Being Scale)
Developed to operationalize "well-being," the QWBS was an attempt to provide an alternative to a cost-benefit analysis (Bowling 1997). This standard HRQOL instrument combines mortality with quality of life estimates and gives a summary of health status as quality adjusted life years. The content of the QWBS scale consists of three dimensions of daily activity: mobility, physical, and social activity. This instrument uses weighted scores that are then transformed into a single number. The QWBS quantifies HRQOL into a single number from 0-1 (death to perfect health). This instrument can also be scored and used to achieve a profile of scores.

Strengths: This instrument can be applied to any disease and can be used in general populations. The instrument has good reliability, content, construct, and criterion validity. The QWBS gives an easy to understand overall impact of medical and mental health score for HIV patients. The QWBS has shown the ability to predict outcomes among HIV patients and includes death, which avoids having death appear to improve the health status of the population. This also permits the ability to distinguish between individuals with similar functional disability by weighting items to consider if the illness is terminal. The QWBS has been shown to correlate with functional ability and broader health status scales. The questionnaire takes about 10-15 minutes to complete and can be given to proxy respondents when a patient is unavailable. The QWBS's universality allows it to be used in policy analysis (Bowling 1997).

Limitations: The QWBS needs to have a meticulously trained interviewer to administer the questionnaire and the interview uses a long, 30-page manual (Bowling 1997). This instrument is weighted more toward physical aspects of HRQOL than psychosocial. This questionnaire also has no HIV specific questions (Hays & Shapiro 1992).

Q-TWIST (Time without disease symptoms and drug toxicity)
Assesses QOL and the quantity of life after adjustment. This instrument was specifically designed to estimate the ZDV impact on QOL (Vanhems et al. 1996).

Strengths: The Q-TWIST estimates both quality of life and quantity of life at the same time (Vanhems et al. 1996).

Limitations: May be difficult to apply outside of clinical trials because symptoms must be correlated with repeated biological tests, it has no psychosocial or behavioral dimensions and has no self-assessment items (Vanhems et al. 1996).