Thisthesisis basedonthefollowing papers,whichwill bereferredto by theirroman numerals

5. ORIGINAL PAPERS
Thisthesisis basedonthefollowing papers,whichwill bereferredto by theirroman
numerals:
I. Hoa NP, ThorsonA, Long NH, Diwan VK. Knowledgeof tuberculosisand
associatedhealth-seekingbehaviouramongrural Vietnameseadultswith a
coughfor at leastthreeweeks.ScandinavianJournal ofPublic Health2003;
31 (Supplement62):59-65.
ll. .HoaNP, Diwan VK, Co NY, ThorsonA. Knowledgeabouttuberculosisand
its treatmentamong new pulmonary TB patientsin the north and central
regionsof Vietnam.InternationalJournal of TuberculosisandLungDisease
2004;8(5):603-608.
1lI. Hoa NP, Diwan VK, ThorsonA. Diagnosisand treatmentof pulmonary
tuberculosisat basic health care facilities in rural Vietnam: a survey of
knowledgeandreportedpracticesamonghealthstaff.HealthPolicy(inpress).
IV. ThorsonA, Hoa NP, Long NH, Allebeck P, Diwan VK. Do womenwith
tuberculosishave a lower likelihood of getting diagnosed?Prevalenceand
casedetectionof sputumsmearpositivepulmonaryTB, a populationbased
studyfromVietnam.Journal ofClinicalEpidemiology2004;57(4):398-402.
V. Hoa NP, ThorsonA. Excessmortality and tuberculosisamongindividuals
with prolongedcough -a population-based,longitudinal study in Vietnam
(submitted).
Theoriginalpapershavebeenprintedwith permissionfromthepublishers.
2

7. CONTENTS
Abstract 1
Originalpapers 2
Abbreviations 3
1. INTRODUCnON 6
1.1.Theglobaltuberculosissituation 6
1.2.Tuberculosiscontrol 7
1.2.1.Controllingtuberculosis-is it feasible? 7
1.2.2.EvolutionofTB control 8
1.2.3.DOTSstrategy 9
1.2.4.Targetsfor TB control 10
1.3.ChallengesfortheDOTSstrategy 11
1.3.1.KnowledgeaboutTB andtheNTP 11
1.3.2.Casedetection 15
1.3.3.Methodsof ensuringtreatmentcompletion 15
1.4.Healtheducationandhealthbehaviour 16
1.4.1.Healtheducation 16
1.4.2.Healthbehaviourchangeasaprocess 16
1.4.3.Therole of healtheducationin currentTB controlstrategy 17
1.5.Vietnam 17
1.5.1.Basicinformation 17
1.5.2.TBepidemiologyandTB control 19
1.6.Aboutthethesis 25
2. OBJECllVES 27
2.1.Generalobjective 27
2.2.Specificobjectives 27
3. METHODS 28
3.1.Studysettings 28
3.2.Studysubjects 33
3.3.Studydesignsanddatacollectionmethods 34
3.4.Mainvariablesanddefinitions 37
3.5.Dataanalysis 38
3.6. Ethicalconsiderations 39
4. RESULTS 41
4.1.PathwaytoTB diagnosis:therole ofTB knowledgeandpractices 41
4.1.1.TBknowledgeamongprolongedcoughcasesandTB patients 41
4.1.2.TBknowledgeandhealthseekingbehaviour 43
4.1.3.TBknowledgeandreportedpracticesamonghealthcarestaff 44
4.2.Casedetection 47
4.2.1.Estimated"true"prevalenceof smearpositiveTB 47
4.2.2.CasedetectionrateoftheNTP 48
4.2.3.SmearpositiveTB notificationratesamongprolongedcoughcases 49
4.3. Mortalityratesamongprolongedcoughcases 49
4

11. A review of the trends of TB in the recent pastshowed that the crude number of TB
patients in 14 Western European countries combined has decreasedregularly since
1974,with an averageannualdecline of 5.4% (Rieder, 1999). In Western Europe,the
lowest rate was found in Denmark and Sweden (7.0/100,000 population in 1992),
(Raviglione et al., 1995). TB mortality has decreased in all Western European
countries during the past century. The TB mortality rate for the early 1990s ranged
from 0.3 to 1.8 per 100,000 population (Rieder, 1995a). In Eastern Europe, TB
notification rates for all countries combined showed an average annual decline of
3.3% in the 1990s,decreasing from 72.7 per 100,000 population in 1975 to 41.8 per
100,000'population in 1991. Mortality was also low in Eastern Europe, ranging
between 0.4-10.7 per 100,000 population (Rieder, 1995a). However, in recent years,
analarming increase in the number of notified TB caseshas beenobserved in Eastern
Europe and in the former USSR. In the Russian Federation,TB incidence rates have
more than doubled from 43.2 to 88.2 per 100,000 population from 1990 to 2001
(WHO, 2002b). In Canada,TB casenotifications and rateshave remained stable since
1987. In 1992, the Canadian TB notification rate was 7.5 per 100,000 population
(Raviglione et al., 1995). In the United States,TB also decreasedfrom 1953 to 1984.
However, from 1985 reported TB casesincreased until 1992. This was attributed to
increasing HIV infections, homelessness,drug abuse,and immigration from countries
where TB is common.
Despite the declines in TB notification rates in Europe and North America during the
past century, TB has not declined in most of the world's low-income countries. There
are a number of reasons for the current TB situation in today's high burden TB
countries including poor knowledge about TB in the community, social stigma
associatedwith TB, limited accessto health care,economic burden, genderinequity in
health service, delayed health care seeking, delayed TB diagnosis, delayed TB
treatmentand non-compliance (Long et al., 1999a; Johanssonet al., 1996; Needham
et al., 1998). InadequateTB knowledge and skills among healthcare staff, insufficient
health infrastructure and lack of diagnostic equipment and TB drugs are factors that
contribute to delayed diagnosis, missed diagnosis and non-compliance with TB
treatment (Hong et al., 1995; Salomao, 1999; Long et al., 1999b). TB control
programmes in low-income countries have not been able to significantly impact the
epidemiology of the disease(Raviglione and Pio,2002).
1.2.2. Evolution ofTB control
Vertical programme versusintegrated programme
The discovery of effective anti-tuberculosis drugs led to vertical TB control programs
in most high-income countries. The programs had their own centra11evelstaff as well
as local level staff who conducted technical control activities. The programs were
often independent of both the general health care infrastructure and other vertical
disease control programs such as leprosy and malaria (Ravig1ione and Pio, 2002).
There was a direct management link from the central TB unit down to TB
hospitals/clinics, mobile X-ray units, and the Bacille Calmette Guerin (BCG) team.
This vertical approachwas successful in high-income countries to reduce the annual
risk of TB infection (Rieder, 1999). The same model was subsequentlyproposed by
the World Health Organization (WHO) for low-income countries. By the late 1950s,it
became clear that, unlike high-income countries, in most low-income countries TB
8