Skip to content

Advertisement

You're viewing the new version of our site. Please leave us feedback.

Learn more

Journal of the International AIDS Society

Open Access

Factors influencing quality of life of people living with HIV in Estonia: a cross-sectional survey

Journal of the International AIDS Society200912:13

https://doi.org/10.1186/1758-2652-12-13

Received: 03 December 2008

Accepted: 16 July 2009

Published: 16 July 2009

Abstract

Background

Identification of factors that determine quality of life is important in order to better tailor health and social care services, and thereby improve the functioning and well being of people living with HIV. The estimated number of people living with HIV in eastern Europe and central Asia is 1.6 million. Little is known about the quality of life of people living with HIV in this region. The main purpose of the present study was to identify the factors influencing quality of life in a sample of HIV-infected persons in Estonia.

Methods

A convenient sample of 451 patients attending three infectious diseases clinics for routine HIV clinical care visits was recruited for a cross-sectional survey. The World Health Organization's Quality of Life HIV instrument was used to measure quality of life of the participants and medical data was abstracted from clinical records.

Results

Good overall quality of life was reported by 42.6% (95% CI: 38.0–47.2%) of the study participants (53% men, 60% self-identify as injecting drug users, 82% <30 years of age, 30% with CD4+ T cell count <300 cells/mm3, and 22% on antiretroviral treatment). We identified the following variables as independent predictors of good overall quality of life: being currently employed or studying (AOR: 2.27, 95% CI: 1.18–4.38); and the absence of HIV-related symptoms (AOR: 2.31, 95% CI: 1.24–4.29).

Conclusion

A comprehensive and competent care system, including health care providers and social workers, is required for an effective response. In addition, social interventions should seek to enhance the economic and employment opportunities for people living with HIV in the region.

Introduction

A patient's well being is determined not only by his or her health status and response to treatment, but also by other social and psychological dimensions. The identification of factors that determine quality of life (QoL) is important in order to better tailor health and social care services, and thereby improve the functioning and well being of people living with HIV (PLHIV).

In addition, the identification of potentially modifiable factors of QoL could help target people in need of additional services in order to improve QoL [1]. Besides physical and mental health-related factors, socio-demographic characteristics, such as age, gender, education, income and employment status, have been found to be strongly associated with the QoL of PLHIV [24].

During the third decade of the AIDS era, new HIV epidemics continue to occur. One of the most recent and rapid increases in the number of new HIV infections in the world has taken place in the newly independent states of the former Soviet Union [5]. The estimated number of PLHIV in eastern Europe and central Asia is 1.6 million (1.2 million–2.1 million) [6]. In eastern Europe, injecting drug users (IDUs) accounted for 62% of all newly diagnosed HIV cases in 2006 [7]. Little is known about the QoL of PLHIV in this region.

The purpose of this study was to examine QoL among Estonian HIV-infected individuals, and to assess the impact of socio-demographic and disease-related variables on QoL in order to facilitate the development of treatment and social care programmes and interventions.

Methods

Setting and sample

In 2005, a cross-sectional survey was conducted using a convenient sample of HIV-infected patients attending for routine clinical care visits. We recruited study subjects from infectious diseases clinics in Tallinn, the capital of Estonia (N = 1), and in the north-eastern Ida-Viru county (N = 2). In total, 58% of the Estonian population live in the capital region and in north-eastern Estonia [8]. Importantly, approximately 90% of all HIV cases in Estonia are diagnosed in Tallinn and north-eastern Estonia [9] and, together, these three infectious diseases clinics serve more than 95% of all HIV-infected patients in care in Estonia [10].

These clinics provide both in-patient and out-patient infectious disease health care services, including HIV-specific services and antiretroviral (ARV) treatment. In each of the three clinics, one physician was contracted for the recruitment of study subjects, and was asked to enrol a minimum of 150 adult HIV-positive patients from an out-patient clinic.

Inclusion criteria for study subjects were that they be: more than 18 years old; have the ability to read and write in Estonian or Russian; and have been aware of their HIV-infection status for more than three months.

After determining eligibility and securing informed consent, all participants filled in the questionnaire designed for self-administration, which required between 45 and 60 minutes to complete. Participants received supermarket food vouchers to the value of approximately USD 10, equivalent to about 100 kroon (EEK), as an incentive for study participation.

Measurements

A self-administered survey was used for socio-demographic, HIV-related risk behaviour and QoL assessment. Clinical characteristics were obtained from medical records.

Specifically:
  1. 1.

    QoL data was collected using the World Health Organization's Quality of Life HIV (WHOQOL-HIV) instrument. The WHOQOL-HIV contains 29 facets, each with four items, which are subsumed in six domains: physical, psychological, level of independence, social, environmental and spiritual. There is also a general facet that measures the overall QoL and general health perceptions (overall QoL). Items are rated on a 5-point Likert interval scale where 1 indicates low, negative perceptions, and 5 indicates high, positive perceptions. Facet scores are the mean of the four items in each facet. Domain scores are obtained by adding the facet means in the respective domain, dividing by the number of facets in that domain, and multiplying by 4, so that scores ranged from 4 (worst possible QoL) to 20 (best possible QoL). Adaptation of the WHOQOL-HIV instrument to the setting and to Estonian and Russian languages has been described elsewhere [11]. In short, Estonian and Russian versions of the WHOQOL-HIV proved to be reliable and valid instruments. Cronbach alpha was above 0.70 for the six domains and the overall QoL and general health facet. Each domain was significantly correlated with the overall QoL and general health facet. Asymptomatic people reported significantly better QoL in physical, psychological and independence domains and related facets compared to those people with symptoms or AIDS [[12]; Rüütel K, unpublished data].

     
  2. 2.

    We also collected data on socio-demographic characteristics (age, gender, education, marital status and employment status) and self-identified route of HIV-infection acquisition.

     
  3. 3.

    Physicians recruiting the patients collected clinical characteristics from hospital records on the basis of a standardized data abstraction form. Data on the stage of HIV infection (no symptoms, symptoms/early HIV disease, and AIDS), duration since diagnosis of HIV (3–6 months, 7–12 months, 1–2 years, 3–5 years, and more than 5 years), CD4 count, co-morbidities (hepatitis B and C, and tuberculosis) and antiretroviral treatment were obtained.

     

Statistical analysis

Data entry was done centrally using Microsoft Access. Statistical analysis was performed with R 2.4.0, a language and environment software for statistical computing and graphics. We used proportions or means with standard deviation (for continuous data) to describe socio-demographic (age, region, gender, education and employment status) and health-related factors (disease stage, routes of infection, CD4 count and time since HIV diagnosis) in different QoL groups.

For the purposes of the factors of QoL analysis, participants were divided into two groups based on the mean score of the facet, "overall quality of life and general health perceptions" (range 1 to 5). Participants with mean scores of >3.0 were categorized as having good QoL, and their counterparts (mean scores of ≤ 3.0) as having poor QoL.

Odds ratios (OR) and 95% confidence intervals (95% CI), together with p-values, were used to identify variables associated with reporting good QoL. A multivariate analysis was performed using logistic regression, taking QoL (good/poor) as the binary dependent variable and the variables related to QoL in the univariate analyses as the covariates to evaluate the independent contribution of variables to QoL.

The magnitude of the association between covariates and QoL in univariate and multivariate analysis was evaluated through odds ratios, together with their corresponding 95% confidence intervals. P-values of less of 0.05 were considered as statistically significant.

Ethical approval was obtained from the Tallinn Medical Research Ethics Committee.

Results

A total of 562 HIV-infected patients were approached for study participation between 1 June and 31 August 2005. Altogether, 451 (80%) were enrolled. The reasons for non-participation were as follows: refusal (50%, 56/111), being aware of HIV-infection status for less than three months (37%, 41/111), and being younger than 18 years at the time of the study (13%, 14/111). In all, 150 patients were recruited in the capital city, Tallinn (33%) and 301 in north-eastern Estonia (67%).

Sample characteristics

Sample characteristics are presented in Table 1. The mean age of the participants was 25 years (SD 6.9 years), and 82% (n = 371) were younger than 30 years of age. More than half of the participants (53%, n = 240) were men. The majority of the participants were of Russian ethnicity (85%, n = 383); the remainder were either ethnic Estonians (10%, n = 45) or representatives of other nationalities (4.4%, n = 20). Close to two thirds (60%, n = 269) self-reported injection drug use (sharing needles) as a potential source of HIV infection; this included 33% of the women (n = 88) participating, and 67% of the men (n = 181). In total, 19% of the participants had been aware of their HIV infection for less than 12 months (n = 87), 24% for one to two years (n = 107), and 54% for more than three years (n = 245). In terms of HIV-related health status, 59% (n = 268) of the respondents were asymptomatic, 36% (n = 163) symptomatic, and 3% (n = 12) had AIDS.
Table 1

Socio-demographic, HIV disease and co-infection related characteristics of the participants

CHARACTERISTIC

N

%

Socio-demographic

  

Gender

  

Male

240

53.2

Female

210

46.6

N.A.

1

0.2

Age

  

≥30 years

80

17.7

<30 years

371

82.3

Place of living

  

Ida-Viru county, north-eastern Estonia

297

65.8

Capital city, Tallinn

132

29.3

Other

22

4.9

Ethnicity

  

Russian

383

84.9

Estonian

45

10.0

Other

20

4.4

N.A.

3

0.7

Education

  

≤9 years of formal education

180

39.9

>9 years of formal education

269

59.7

N.A.

2

0.4

Occupation

  

Unemployed

161

35.7

Working or studying

284

63.0

N.A.

6

1.3

Partnership

  

Legally married

106

23.5

Other

336

74.5

N.A.

9

2.0

HIV disease related

  

HIV transmission category (self-report)

  

Injecting drug use

269

59.7

Sexual transmission

163

36.1

Other

15

3.3

N.A.

4

0.9

Time of HIV diagnosis

  

<12 months

87

19.3

1 to 2 years

107

23.7

≥3 years

245

54.3

N.A.

12

2.7

Stage of HIV-infection

  

No symptoms

268

59.4

Early HIV disease

163

36.1

AIDS

12

2.7

N.A.

8

1.8

CD4 count

  

≥300 cells/mm3

240

53.2

<300 cells/mm3

102

22.6

N.A.

109

24.2

Current ARV treatment

  

Yes

97

21.5

No

352

78.0

N.A.

2

0.4

Co-infections

  

Ever had tuberculosis

  

Yes

10

2.2

No

439

97.4

N.A.

2

0.4

Ever had hepatitis B or C

  

Yes

268

59.4

No

182

40.4

N.A.

1

0.2

N.A.: Data not available

Quality of life

The mean scores for the overall QoL and general health and six domains for the sample are presented in Table 2.
Table 2

Mean scores for overall quality of life and general health perceptions and for six domains

 

Mean score (SD)

Overall QoL and general health perceptions

2.9 (0.8)

Physical

13.3 (3.2)

Psychological

13.7 (2.3)

Independence

14.5 (3.2)

Social relationships

13.9 (2.6)

Environment

12.3 (2.1)

Spiritual

12.8 (2.9)

In a univariate analysis, the factors which significantly increased the likelihood of good QoL in the facet, "overall QoL and general health perceptions", included: female gender (48% vs 37% among males, p = 0.03); age under 30 years (45% vs 29%, p = 0.009); living in the capital city (57% vs 36% in Ida-Viru county, p = 0.0001); being employed or studying (52% vs 38% among unemployed, p < 0.0001); being legally married (55% vs 39% among people in other types of relationships, p = 0.004); being infected with HIV sexually, not through injecting drug use, based on self-report on the mode of HIV acquisition (53% vs 38%, p = 0.002); being aware of their infection for less than 12 months (54% vs 41%, p = 0.02); having no HIV-related symptoms, based on abstraction from clinical records (51% vs 28%, p < 0.0001); and CD4 count above 300 cells/mm3, based on abstraction from clinical records (54% vs 32%, p = 0.0003) (Table 3).
Table 3

Univariate and multivariate factors associated with good quality of life among HIV-infected persons in Estonia

Characteristic

Good QoL

OR

95% CI

p

AOR

95% CI

p

 

N

%

      

Socio-demographic

        

Gender

        

Male

89

37.4

1.0

  

1.0

  

Female

100

47.6

1.52

1.04–2.22

0.03

0.61

0.33–1.13

0.1

Age

        

≥30 years

23

28.7

1.0

  

1.0

  

<30 years

166

45.0

2.03

1.20–3.43

0.009

1.55

0.74–3.25

0.2

Place of living

        

Ida-Viru county, north-eastern Estonia

105

35.5

1.0

  

1.0

  

Capital city, Tallinn

74

56.5

2.4

1.56–3.57

0.0001

1.08

0.62–1.88

0.8

Ethnicity

        

Russian

157

42.3

1.0

     

Estonian

24

55.8

1.7

0.91–3.25

0.09

   

Education

        

≤9 years

69

38.3

1.0

     

>9 years

120

44.9

1.31

0.89–1.93

0.2

   

Occupation

        

Unemployed

123

38.2

1.0

  

1.0

  

Employed and/or studying

65

52.0

3.13

2.04–4.76

<0.0001

2.27

1.18–4.38

0.01

Partnership

        

Other

129

38.6

1.0

  

1.0

  

Legally married

58

54.7

1.92

1.24–2.99

0.004

1.26

0.66–2.41

0.5

HIV disease related

        

HIV transmission category (self report)

        

Injecting drug use

89

37.7

1.0

  

1.0

  

Sexual transmission

86

53.4

1.89

1.27–2.86

0.002

1.37

0.73–2.59

0.3

Time of HIV diagnosis

        

≥12 months ago

99

40.6

1.0

  

1.0

  

<12 months ago

47

54.0

1.79

1.1–2.86

0.02

1.2

0.60–2.45

0.6

Stage of HIV-infection

        

Early HIV disease/AIDS

49

28.2

1.0

  

1.0

  

No symptoms

136

50.9

2.65

1.76–3.98

<0.0001

2.31

1.24–4.29

0.008

CD4 count

        

<300 cells/mm3

32

31.7

1

  

1.0

  

≥300 cells/mm3

128

53.6

2.49

1.52–4.06

0.0003

1.72

0.91–3.26

0.09

Current ARV treatment

        

No

136

40.2

1.0

     

Yes

52

48.1

1.37

0.89–2.13

0.1

   

Co-infections

        

Tuberculosis

        

Yes

4

40.0

1

     

No

184

42.1

1.09

0.3–3.92

0.9

   

Hepatitis B and/or C co-infection

        

Yes

106

39.8

1

     

No

83

45.6

1.27

0.86–1.85

0.2

   

In multivariate analysis (logistic regression model), after including variables significant in univariate analysis into the model, being currently employed or studying (AOR: 2.27, 95% CI: 1.18–4.38), and the absence of HIV-related symptoms (AOR: 2.31, 95% CI: 1.24–4.29) were identified as independent predictors of good QoL (Table 3).

Discussion

This is the first study describing factors influencing QoL of HIV-infected persons from an eastern European country, a region that has witnessed a relatively recent HIV epidemic driven by injection drug use. It has been suggested that transmission of 80% of HIV infections in former Soviet Union countries is attributable to sharing needles and syringes [7].

The mean overall QoL score for the whole sample (2.90 ± 0.84) was slightly lower than that reported from similar studies from other regions. O'Connell and colleagues have described a mean overall QoL score (measured by WHOQOL) of 3.2 ± 0.88 for a sample of 590 HIV-infected persons from six culturally diverse sites in Australia, Brazil, India (two sites), Thailand and Zimbabwe [13].

Further, we can argue that our study overestimated the QoL of PLHIV in Estonia. Several studies have documented better physical health-related QoL among former IDUs than in current IDUs [14, 15]. IDUs often struggle with multiple health risks due to social, economic and psychological factors. Getting HIV care may not be their top concern because they face other more pressing daily challenges, such as addiction, poverty, incarceration, homelessness, depression, mental illness and past trauma [16].

Given this and the highly stigmatised nature of illegal drug use, both former and current injecting drug users are less likely to receive HIV-related medical care – this is the case in Estonia – and hence they may be under-represented in the clinical samples of PLHIV. In our sample, 60% of participants reported having used injecting drugs.

In our study, the independent and most influential contributors to the general QoL were a person's employment status and clinician-recorded HIV-disease stage. The employed participants, including those who were studying, were more likely to have good general QoL than their not-working counterparts. Our findings are consistent with previous research, which has demonstrated that employment (and higher income) is associated with a better QOL among PLHIV [17, 18].

Controlling for disease severity, employed individuals report significantly higher level of perceived QoL than those who are unemployed [1921]. Besides financial benefits, employment also provides a source for structure, social support, role identity and meaning. In addition, stable income and employment have been associated with adherence to highly active antiretroviral treatment [22].

Employment may also provide resources, which buffer the effects of the stress of HIV infection and thus serves to maintain a sense of quality of life [21]. Therefore, return-to-work programmes and other interventions to enhance the economic and employment opportunities are important for PLHIV in eastern Europe and the Russian Federation. Here, young injecting drug users are the main HIV risk group, and unemployment among them is high.

According to our results, asymptomatic patients reported better QoL than those with symptoms or AIDS diagnosis. This factor is amenable for clinical interventions. Quality of life can be altered by both the immediate effects and the longer-term consequences of antiretroviral treatment. Persons with advanced HIV disease and low QoL scores have demonstrated significant improvements in QoL with ARV treatment [23, 24].

Other disease-related factors and co-infection with hepatitis B or C were not associated with better QoL in our sample. Nevertheless, given the extremely high (>90%) hepatitis C infection rates among IDUs in the region and the high proportion of IDUs among PLHIV [25, 26], co-infections with hepatitis B or C warrant attention. Several previous studies have suggested that hepatitis C infection significantly reduces health-related QoL [27, 28], and this effect can be inversed with antiviral treatment [29]. Chronic hepatitis B infection similarly negatively impacts on QoL [30].

With improvements in HIV treatment, liver disease has become a major cause of hospitalisation and death in PLHIV and complications related to hepatitis B or C co-infection are becoming an increasingly important medical issue. Proper prevention, screening and management of co-infections are of great concern given the high rates of hepatitis B and C infections in Estonia.

Limitations

Our study had limitations. Given the design of the study, we are able to demonstrate neither causality nor the direction of the described associations. The degree to which the study is representative of the larger HIV-infected population is influenced by the potential selective factors associated with recruiting from HIV treatment settings.

Our results most likely overestimate the QoL of those infected with HIV, as we have discussed. We were successful in recruiting people who are in HIV care in Estonia by sampling from the facilities that provide 95% of HIV care in the country. We also achieved a high participation rate in a specified study period.

To decrease the potential for social desirability bias, we used a self-administered survey instrument for risk behaviour data collection. To enhance the validity of the data on health status, we complemented self-reports with clinical data abstracted from clinical records.

Conclusion

In conclusion, HIV disease status and employment were the important factors influencing QoL of PLHIV in Estonia. A comprehensive and competent care system, including medical staff and social workers, is required for an effective response. In addition, social interventions should seek to enhance the economic and employment opportunities for PLHIV.

This data contributes to the input needed for planning health care services and interventions that address QoL improvement for PLHIV in eastern Europe and central Asia.

Declarations

Acknowledgements

This study was funded by: the Global Fund to Fight HIV, Tuberculosis and Malaria's programme, "Scaling up the response to HIV in Estonia"; the Embassy of the United States of America in Estonia's project, "HIV and human rights: reducing the stigma on three levels: prevention, quality of services and policy"; and the grant No. R01 TW006990 from the Fogarty International Center, National Institutes of Health, USA.

The authors are grateful to the participants and the study team for their cooperation.

Authors’ Affiliations

(1)
Department of Illegal Drug Use and Infectious Diseases Prevention, National Institute for Health Development
(2)
Department of Public Health, University of Tartu
(3)
Department of Chronic Diseases, National Institute for Health Development

References

  1. McDonnell KA, Gielen AC, O'Campo P, Burke JG: Abuse, HIV status and health-related quality of life among a sample of HIV positive and HIV negative low income women. Quality of Life Research 2005, 14: 945–957.View ArticlePubMedGoogle Scholar
  2. Cowdery JE, Pesa JA: Assessing quality of life in women living with HIV infection. AIDS Care 2002, 14 (2) : 235–245.View ArticlePubMedGoogle Scholar
  3. Wachtel T, Piette J, Mor V, Stein M, Fleishman J, Carpenter C: Quality of life in persons with human immunodeficiency virus infection: Measurement by the medical outcomes study instrument. Ann Intern Med 1992, 116: 129–137.PubMedGoogle Scholar
  4. Murri R, Fantoni M, Del Borgo C, Visona R, Barracco A, Zambelli A, Testa L, Orchi N, Tozzi V, Bosco O, Wu AW: Determinants of health-related quality of life in HIV-infected patients. AIDS Care 2003, 15 (4) : 581–590.View ArticlePubMedGoogle Scholar
  5. Rüütel K, Uusküla A: HIV epidemic in Estonia in the third decade of AIDS era. Scandinavian Journal of Infectious Diseases 2005, 38: 181–186.Google Scholar
  6. UNAIDS/WHO: AIDS Epidemic Update. Geneva 2007.Google Scholar
  7. EuroHIV: HIV/AIDS Surveillance in Europe. Mid-year report. 2007., (76) : Google Scholar
  8. Database of Statistical Office of Estonia [http://www.stat.ee/rahvastik]
  9. Database of Estonian Health Protection Inspectorate [http://www.tervisekaitse.ee/?page=102]
  10. Database of National Institute for Health Development [http://www.tai.ee/?id=4043]
  11. Rüütel K, Uusküla A, Minossenko A, Loit HM: Quality of life of people living with HIV and AIDS in Estonia. Cent Eur J Public Health. 2008, 16 (3) : 111–115.PubMedGoogle Scholar
  12. Rüütel K, Loit HM, Uusküla A: Psychometric properties of Russian version of WHOQOL-HIV instrument. The 5th European Conference on Clinical and Social Research on AIDS and Drugs: 28–30 April 2009; Vilnius, Lithuania Abstract no PE3.3/7.Google Scholar
  13. WHOQOL-HIV Group: Preliminary development of the World Health Organization's Quality of Life HIV Instrument (WHOQOL-HIV): analysis of the pilot version. Social Science and Medicine 2003, 57: 1259–1275.View ArticleGoogle Scholar
  14. Preau M, Protopopescu C, Spire B, Sobel A, Dellamonica P, Moatti JP, Carrieri MP: Health related quality of life among both current and former injection drug users who are HIV-infected. Drug Alcohol Depend. 2007, 86 (2–3) : 175–182.View ArticlePubMedGoogle Scholar
  15. Costenbader EC, Zule WA, Coomes CM: The impact of illicit drug use and harmful drinking on quality of life among injection drug users at high risk for hepatitis C infection. Drug Alcohol Depend. 2007, 89 (2–3) : 251–258.View ArticlePubMedGoogle Scholar
  16. Galea S, Vlahov D: Social determinants and the health of drug users: socioeconomic status, homelessness, and incarceration. Public Health Rep 2002, 117 (Suppl 1) : S135–145.PubMedGoogle Scholar
  17. Blalock AC, MacDaniel JS, Farber EW: Effect of employment on quality of life and psychological functioning in patients with HIV/AIDS. Psychosomatics 2002, 43: 400–404.View ArticlePubMedGoogle Scholar
  18. Worthington C, Krentz HB: Socio-economic factors and health-related quality of life in adults living with HIV. International Journal of STD & AIDS 2005, 16 (9) : 608–614.View ArticleGoogle Scholar
  19. Low-Beer S, Chan K, Wood E, Yip B, Montaner JS, O'Shaughnessy MV, Hogg RS: Health related quality of life among persons with HIV after the use of protease inhibitors. Quality of Life Research 2000, 9: 941–949.View ArticlePubMedGoogle Scholar
  20. Mrus JM, Leonard AC, Yi MS, Sherman SN, Fultz SL, Justice AC, Tsevat J: Health-related quality of life in veterans and nonveterans with HIV/AIDS. J Gen Intern Med 2006, 21: S39–47.View ArticlePubMedGoogle Scholar
  21. Sowell RL, Seals BF, Moneyham L, Demi A, Cohen L, Brake S: Quality of life in HIV-infected women in the south-eastern United States. AIDS Care 1997, 9 (5) : 501–512.View ArticlePubMedGoogle Scholar
  22. Carballo E, Cadarso-Suarez C, Carrera I, Fraga J, de la Fuente J, Ocampo A, Ojea R, Prieto A: Assessing relationships between health-related quality of life and adherence to antiretroviral therapy. Quality of Life Research 2004, 13: 587–599.View ArticlePubMedGoogle Scholar
  23. Cohen C, Revicki DA, Nabulsi A, Sarocco PW, Jiang P, the Advanced HIV Disease Ritonavir Study Group: A randomized trial of the effect of ritonavir in maintaining quality of life in advanced HIV disease. AIDS 1998, 12: 1495–1502.View ArticlePubMedGoogle Scholar
  24. Nieuwkerk PT, Gisolf EH, Reijers MHE, Lange JMA, Danner SA, Sprangers MAG: Long-term quality of life outcomes in three antiretroviral treatment strategies for HIV-1 infection. AIDS 2001, 15: 1985–1991.View ArticlePubMedGoogle Scholar
  25. Tefanova V, Tallo T, Kutsar K, Priimägi L: Current trends in the epidemiology of viral hepatitis B and C in Estonia. EpiNorth 2005, 3 (6) : 57–61.Google Scholar
  26. Uusküla A, McNutt LA, Dehovitz J, Fischer K, Heimer R: High prevalence of blood-borne virus infections and high-risk behaviour among injecting drug users in Tallinn, Estonia. Int J STD AIDS 2007, 18 (1) : 41–46.View ArticlePubMedGoogle Scholar
  27. Foster G, Goldin R, Thomas H: Chronic hepatitis C virus infection causes a significant reduction in quality of life. Hepatology 1998, 27: 209–212.View ArticlePubMedGoogle Scholar
  28. Bonkovsky HL, Wooley JM: The Consensus Interferon Study Group. Reduction of health-related quality of life in chronic hepatitis C and improvement with interferon therapy. Hepatology 1999, 29: 264–210.View ArticlePubMedGoogle Scholar
  29. Bonkovsky HL, Snow KK, Malet PF, Back-Madruga C, Fontana RJ, Sterling RK, Kulig CC, Di Bisceglie AM, Morgan TR, Dienstag JL, Ghany MG, Gretch DR, HALT-C Trial Group: Health-related quality of life in patients with chronic hepatitis C and advanced fibrosis. J Hepatol. 2007, 46 (3) : 420–431.View ArticlePubMedGoogle Scholar
  30. Herdman MJ, Ossa D, Briggs AS, Tafesse E, Iloeje U, Lozano-Ortega G, Levy AR: Impact on quality of life of health states induced by chronic hepatitis B infection: estimates from uninfected and infected persons in Spain. J Clin Virology 2006, 36 (Suppl 2) : S78.View ArticleGoogle Scholar

Copyright

© Rüütel et al. 2009

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Advertisement