Retention and risk factors for attrition among adults in antiretroviral treatment

programs in Tanzania, Uganda and Zambia

Olivier KooleInstitute of Tropical Medicine, Antwerp

ICRH-MozambiqueAIDS 2012 - Turning the Tide Together

Study Team• Family Health International (FHI 360)• Muhimbili University of Health and Allied

Sciences, Tanzania• Infectious Diseases Institute, Makerere

University Medical School, Uganda• Tropical Diseases Research Centre,

Zambia• Institute of Tropical Medicine, Belgium • Massachusetts General Hospital, USA • Centers for Disease Control and

Prevention, USA

• Gideon Kwesigabo• Fred Wabwire-Mangen• Modest Mulenga• David Bangsberg• Joris Menten• Robert Colebunders• Sharon Tsui• Eric Van Praag• Kwasi Torpey• Ya Diul Mukadi• Leine Stuart• Julie Denison• Andrew Auld• Simon Agolory• Seymour Williams• Jonathan Kaplan• Aaron Zee

Context• Massive scale-up of ART: worldwide 8 million

people on ART, 6.5 in sub-Saharan Africa • Greatest increase in coverage in SSA• Importance of retention and adherence for

good clinical outcomes• Retention: critical determinant of adherence

and key indicator of quality of ART programs

Objectives

Primary• To characterise the current level of retention of

patients on ART across multiple programme settings

Secondary• To identify important predictors of retention in care,

including both individual risk factors and programme characteristics

Study Population & Sites• Retrospective cohort study• Study Population

– 18 years and older at ART initiation at study site

– Initiated 3 ARVs at least 6 months prior to data collection

• Study sites– 3 countries – 6 sites per country,

purposively selected

UGANDA

TANZANIA

ZAMBIA

Source of data

• Retrospective cohort study – medical chart review– April to August 2010, 250 medical charts/site

randomly selected and reviewed: clinical records, laboratory register and pharmacy logbook

– June to July 2011, Health Care Manager questionnaire at 18 sites for program characteristics

Sampling• Sampling frame: all

patients ever started on ART at that site

• Random sample of 250 medical charts/site

• Replacement strategy for ineligible patients

• Screening logs: – eligible and abstracted– ineligible– missing

Methods• Retained patient: visit to one of the following

services during the 90 days prior to data abstraction– Clinic– Laboratory– Pharmacy

• Kaplan-Meier analysis• Attrition (=event): death or LTFU

– transfer-outs censored at the time of transfer• Predictor analysis: Cox proportional hazard model,

shared frailty effect

Patient accountingNumber of files randomly selected 7,755

Number of ineligible files 1,951

Number of missing files 1,310

Number of files extracted 4,494

Number of duplicate files extracted 84

Number of files with missing start date of ART 19

Number of ineligible charts (<18 years or abstraction date not within 6 months of first ART):

3

Number in the analysis-set 4,388

Number in the analysis-set with one site (241 patients) dropped

4,147

Country Number of sites Number of patients

Tanzania 6 1,458

Uganda 6 1,472

Zambia 5 1,217

Selected characteristics at baseline (ART initiation)

Characteristic n (%)

Total number patients 4,147 (100.0)

Age (year), mean (SD) 36.9 (9.4)

Gender, n (%)

Female 2,670 (64.4)

Calendar year of start ART, n (%) < 2004 141 (3.7)

2005 646 (15.6)

2006 785 (18.9)

2007 960 (23.2)

2008 868 (20.9)

2009-2010 747 (18.0)

Characteristic n (%)

CD4 cell count: median (IQR)

134 (63-206)

Missing 1,006 (24.3)

WHO stage , n (%)

I & II 1,334 (32.2)

III 1,600 (38.6)

IV 597 (14.4)

Missing 616 (14.9)

Functional status , n (%)

Working 2,140 (51.6)

Ambulatory 686 (16.5)

Bedridden 115 (2.8)

Missing 1,206 (29.1)

Selected program characteristics (1)

Characteristic n, %

Total number of facilities 18

Level health facility

National referral 4 (22)

Provincial/Regional 4 (22)

District 6 (33)

Primary or community based

4 (22)

Type health facility

Government 9 (50)

Mission 5 (28)

Non-religious NGO 4 (22)

Characteristic n, %

Number of adults on ART

< 2000 8 (44)

2000-4000 6 (33)

> 4000 4 (22)

Setting

Rural/peri-urban 8 (44)

Urban 10 (56)

Program characteristics (2)

Characteristic n

Total number of facilities 18

Refill frequency after 6 months on ARTMonthly 6 (33)

Every 2 months 8 (44)

Every 3 months 4 (22)

Three counseling sessions required before ART initiationNo 4 (22)

Yes 14 (78)

Physician based care

No 3 (17)

Yes 15 (83)

Characteristic n

Buddy required to initiate ARTNo 3 (17)

Yes 15 (83)

Home based care

No 8 (44)

Yes 10 (56)

ARV dispensing in community (= any dispensing outside the clinic)No 13 (72)

Yes 5 (28)

Months since start ART

Per

cent

age

reta

ined

0 6 12 24 36

020

4060

8010

0

TanzaniaUgandaZambia

Levels of retention

Model building - risk factors for attrition

Individual characteristics

Significant and selected (p<0.1) Significant and not selected- Lower age- Male gender- Increasing years since program active- Increasing WHO stage- Weight loss > 10% body mass- Fever > 1 month- Lower CD4 count - Poorer functional status

- Higher distance to clinic- Lower TLC count - Lower Hb level - Candidiasis - Wasting

Program characteristics (p<0.2)

- Level of health facility- Type of health facility- Dispensing of ARVs at community level- Buddy needed for ART initiation

Risk factors of attrition - Multivariable analysis (1)

Patient baseline characteristics Adjusted Hazard Ratio (95% CI)

Age at start

18-29 years 1

≥ 30 years 0.77 (0.67 – 0.88)

Gender

Women 1

Men 1.28 (1.14 – 1.43)

Year of start ART since program active( / year)

1.13 (1.08 – 1.19)

WHO stage at start ART

I & II 1

III 1.10 (0.94 – 1.29)

IV 1.60 (1.32 – 1.93)

Missing 1.29 (1.10 – 1.58)

Risk factors of attrition - Multivariable analysis (2)

Patient baseline characteristics Adjusted Hazard Ratio (95% CI) Absolute values CD4 cell count (cells/µl)

5 1.30 (1.11 – 1.53)

20 1.15 (1.06 – 1.26)

50 1.06 (1.02 – 1.10)

100 (average value) 1

200 0.94 (0.91 – 0.98)

Missing 1.14 (1.01 – 1.30)

Risk factors of attrition - Multivariable analysis (3)Patient baseline characteristics Adjusted Hazard Ratio (95% CI)

Weight loss > 10%

No 1

Yes 1.17 (1.00 – 1.37)

Functional status

Working 1

Ambulatory 1.50 (1.28 – 1.75)

Bedridden 2.08 (1.58 – 2.74)

Missing 1.23 (1.04 – 1.45)

Program characteristics Adjusted Hazard Ratio (95% CI)

ARV dispensing in community

No 1

Yes 0.61 (0.42 – 0.88)

Lower retention amongst men in programs without community dispensing but similar in

programs with ARV dispensing

More difficult for men to come to clinic for drug pick-up?

Hazard Ratio (95% CI) Female – no community distribution 1

Male – no community distribution 1.36 (1.20 – 1.54)

Female – with community distribution 0.68 (0.47 – 1.02)

Male – with community distribution 0.66 (0.43 – 1.00)

Conclusion• Wide variability in retention rates among

different models of care• Importance of community ARV dispensing

– Mobile clinics?– Community pharmacies?– Community ART groups?

• Particularily needed for– Men – Younger persons– The very sick

Special thanks to our funders and partners:

Extra-Selected characteristics at baseline (ART initiation) (2)

Opportunistic infections n (%)

Total number patients 4,147 (100.0)

Weight loss > 10% 841 (20.3)

Fever > 1 month 613 (14.8)

Pulmonary TB 491 (11.8)

Chronic diarrhoea > 1 month 482 (11.6)

Oral candidiasis 269 (6.5)

Wasting syndrome 209 (5.0)

Percentage of selected numbers not found

Number Retention rate

Sites Patients 1 Yr 2 Yr 3 Yr HR (95% CI) P-value

<10% 6 1,465 63.6 53.5 45.6 1 <0.001

≥10% - <20% 6 1,475 88.1 82.4 78.6 0.31 (0.21-0.54)

≥20% 6 1,207 85.1 78.3 73.7 0.37(0.22-0.62)

Extra-Correction for sampling