Since publication use of the WHOQOL-Bref has rapidly risen. However, as yet no population norms have been published as a reference point against which researchers can interpret their findings. This study provides preliminary population norms for this purpose. Randomly sampled community residents from two studies were pooled and used to examine the properties of the WHOQOL-Bref by age group, gender and health status. The results showed that general norms for the WHOQOL-Bref domains were 73.5 (SD=18.1) for the Physical health domain, 70.6 (14.0) for Psychological wellbeing, 71.5 (18.2) for Social relationships and 75.1 (13.0) for the Environment domain. In general scores declined slightly by age group. For females scores were stable across the lifespan with an accelerated decline after the age of 60 years. Males exhibited a more consistent and even decline across the lifespan. There were significant differences in WHOQOL-Bref scores when reported by health status, with those in poor health obtaining scores that were up to 50% lower than those in excellent health. Effect sizes between different health status levels are reported. These preliminary norms and effect sizes may be used as reference points for interpreting WHOQOL-Bref scores. They provide additional information to the numerous national studies already reporting on the validity of the WHOQOL-Bref.

Interpreting the WHOQOL-Bref: Preliminary Population Norms and Effect Sizes.

In this study, the psychometric properties of a quality of life scale, the WHOQOL-Bref, were examined in a population of 533 Dutch adult psychiatric outpatients. Participants underwent two semistructured interviews in order to obtain Axis-I and II diagnoses, according to DSM-IV. Besides the WHOQOL-Bref they also completed questionnaires for measuring psychopathological symptoms (SCL-90) and perceived social support (PSSS). Scores on 25 of the 26 questions of the WHOQOL-Bref had a good distribution. Similar to previous findings, exploratory factor analysis revealed a four-factor structure. A priori expected associations were found between the domains of the WHOQOL-Bref, on the one hand, and dimensions of the SCL-90 and the PSSS-score, on the other hand, indicating good construct validity. The internal consistency of the four domains of the WHOQOL-Bref ranged from 0.66 to 0.80. Domain scores of the WHOQOL-Bref correlated around 0.92 with the WHOQOL-100 domain scores. Relatively low correlations were found between demographic characteristics (age and sex) and WHOQOL-Bref domain scores. It is concluded that the content validity, construct validity, and the reliability of the WHOQOL-Bref in a population of adult Dutch psychiatric outpatients are good. The WHOQOL-Bref, therefore, is an adequate measure for assessing quality of life at the domain level in a population of adult psychiatric outpatients.

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Content validity, construct validity, and reliability of the WHOQOL-Bref in a population of Dutch adult psychiatric outpatients

The study aim was to identify covariates of smoking status and readiness to quit that encompassed key sociodemographic and health status variables, health-related quality of life, drug use and unprotected sex, and tobacco use variables in a cohort of low-income persons living with HIV. We also examined the impact of HIV diagnosis on smoking cessation. The sample (N5428) was mostly male (59%) and Black (53%) or Hispanic (30%), and had a high school education or less (87%). Mean age was 40 years. Two-thirds of participants were current smokers, 19% former smokers, and 16% never smokers. Current smokers smoked a mean of 16 cigarettes/day for 22 years; 42% were in the precontemplation stage of readiness to quit smoking, 40% were contemplators, and 18% were in preparation. Most current smokers (81%) reported receiving medical advice to quit smoking. Multivariate logistic regression analyses indicated that current smokers, compared with former smokers, were more likely to use illicit drugs, perceive a lower health risk for continued smoking, and report less pain. Current smokers, compared with nonsmokers (former and never smokers), were more likely to report greater illicit drug use in their lifetime, current illicit drug use, and less pain. A multiple linear regression indicated that greater current illicit drug use, greater emotional distress, and a lower number of quit attempts were associated with lower stage of readiness to quit smoking. These findings confirm a high prevalence of smoking among HIV-infected persons and suggest a complex interplay among drug use, pain, and emotional distress that impact smoking status and, among smokers, readiness to quit. Tobacco control programs for HIV-infected persons should build motivation to quit smoking and address salient barriers to cessation—such as comorbid drug use, emotional distress, pain, and access to and coverage for treatment—and should educate smokers regarding the HIV-specific health benefits of cessation.

Tobacco use and readiness to quit smoking in low-income HIV-infected persons.

Cognitive Radio Technology

The aim of this study was to examine the validity and reliability of the Polish WHOQOL - Bref in a sample of 908 respondents. The Bref is a generic quality of life (QoL) instrument designed for cross - cultural use. Correlational and multivariate analyses confirmed the relevancy of individual items and domains supporting the construct validity of the scale. Multiple regression analyses of the domain scores with two overall questions (dependent variable) showed that all four domains made a significant contribution in explaining the variance in overall QoL. The psychological domain made the strongest contribution (unstandardized B coefficient = 0.10, r2 = 0.41), followed by the social, environmental and physical domains. When overall health satisfaction was considered as the dependent variable, the physical domain contributed most strongly (unstandardized B coefficient = 0.21, r2= 0.43) followed by the psychological and environmental domains. Exploratory factor analyses resulted in a four factors solution with 24 items explaining 49.6% of the cumulative variance. Confirmatory factor analyses lended marginal support for the goodness of fit of the four-domain model. The physical domain was found to be strongest in differentiating between unhealthy and healthy subjects, followed by psychological and social domains. Acceptable internal consistency was shown with Cronbach's alpha coefficients being greater than 0.70 for all domains with the exception of the social domain. Further exploration of the scales validity and conceptual clarity need further testing in Polish and international samples.

Quality of life in Polish respondents: psychometric properties of the Polish WHOQOL-Bref.

We studied the reliability and validity of the World Health Organization quality of life (WHOQOL) assessment instrument in patients with human immunodeficiency virus (HIV) infection. WHOQOL-BREF was used to assess 136 HIV-infected outpatients. The results were analyzed and compared with data from 213 healthy persons. The Cronbach's alpha for internal consistency ranged from 0.74 to 0.85 across domains in HIV-infected patients. The test-retest reliability ranged from 0.64 to 0.79 across domains at average 4-week retest interval. Factor analysis identified four major factors: social, psychological, environment, and physical, consistent with the four domains of the instrument. The scores of all four domains correlated positively with self-evaluated health status and happiness (r range: 0.52-0.60 and 0.55-0.73 across domains, respectively), and correlated negatively with the number and severity of symptoms (r range: -0.40 to -0.47 and -0.41 to -0.52, respectively). The scores of physical, psychological and social domains, but not the environment domain, discriminated between healthy persons and HIV-infected patients (all p < 0.01). We conclude that the WHOQOL-BREF can be a useful quality-of-life instrument in patients with HIV infection.

Validation of the World Health Organization quality of life instrument in patients with HIV infection

4G and other wireless systems are currently hot topics of research and development in the communication field. Broadband wireless systems based on orthogonal frequency division multiplexing (OFDM) often require an inverse fast Fourier transform (IFFT) to produce multiple subcarriers. In this paper, we present the efficient implementation of a pipeline FFT/IFFT processor for OFDM applications. Our design adopts a single-path delay feedback style as the proposed hardware architecture. To eliminate the read-only memories (ROM's) used to store the twiddle factors, the proposed architecture applies a reconfigurable complex multiplier and bit-parallel multipliers to achieve a ROM-less FFT/IFFT processor, thus consuming lower power than the existing works. The design spends about 33.6K gates, and its power consumption is about 9.8mW at 20MHz.

A novel low-power 64-point pipelined FFT/IFFT processor for OFDM applications

This paper presents the architecture and implementation of a single-chip VLSI for the two-dimensional discrete wavelet transform (2-D DWT) decomposition. This nonseparable based architecture uses a parallel-systolic filter structure to compute all the resolution levels of the DWTs, such that the input samples can be processed at the rate of one sample per clock cycle. The chip was fabricated in a 0.6 /spl mu/m CMOS technology and packaged as a 48-pin DIP. For the computation of an N/spl times/N still image with a filter length L, this chip needs N/sup 2/+N clock cycles and N(2L-1) memory storage; for continuous picture such as video signal, its average computation time per picture is about N/sup 2/ only.

VLSI implementation of 2-D discrete wavelet transform for real-time video signal processing

We present a VLSI architecture for the separable two-dimensional discrete wavelet transform (DWT) decomposition. Using a computation-schedule table, we show how the proposed separable architecture uses only a minimal number of filters to generate all levels of DWT computations in real time. For the computation of an N/spl times/N 2-D DWT with a filter length L, this architecture spends around N/sup 2/ clock cycles, and requires 2NL-2N storage units, 3L multipliers, as well as 3(L-1) adders.

Design of an efficient VLSI architecture for 2-D discrete wavelet transforms

In this paper, a novel low-power Viterbi decoder with soft decision is proposed. For the branch metric of the Viterbi decoder, our design employs a soft-decision method to improve its correction capability. In order to find the survivor path efficiently, we modify the classical Viterbi decoding algorithm into a new one. This new algorithm is similar to the register-exchange method with lower latency, but using RAM instead of register banks for recording the output bit-stream of the survivor path. Hence, our design can provide a low-power design. Finally, the chip of this design consumes about 28.6K gates using TSMC 0.18 μm CMOS technology. The power consumption of our chip is about 19.5mW at 100MHz.

Chu Yu

Papers

Validation of the World Health Organization quality of life instrument in patients with HIV infection

A novel low-power 64-point pipelined FFT/IFFT processor for OFDM applications

VLSI implementation of 2-D discrete wavelet transform for real-time video signal processing

Design of an efficient VLSI architecture for 2-D discrete wavelet transforms

Design of a low power viterbi decoder for wireless communication applications