# Presentation: 042310

## HIV Screening and Care:Clinical Outcomes, Transmission and Cost 

- A. David Paltiel, PhD
*Yale University School of Medicine*
- May 9, 2007
*National Institute on Drug Abuse*
*Bethesda, MD*

## Common misconceptions about                cost-effectiveness analysis
Findings from recent evaluations
Findings on the survival benefits of AIDS treatments in the United States

- Findings from recent evaluations
- Findings on the survival benefits of AIDS treatments in the United States

- Road Map

## Cost-effectiveness: Common Misconception #1

- “Cost-Effective” = “Cheap”
- “Cost-Effective” = “Saves Money”

## Cost-effectiveness is about Value for Money

- comparative assessment of “worth” or “return on investment”
- the cost effectiveness ratio:

- Cost-effectiveness is about Value for Money

**Net Change in Cost ($)**

**Net Change in Health Effect (LY; QALY)**

- can be employed to compare competing claims on scarce resources

## Cost-effectiveness of Chronic Disease Screening

- Cost-effectiveness of Chronic Disease Screening

- 					 	C-E ratio
- Screening Program			($/QALY) 	Reference
- Hypertension 				$80,400 		Littenberg
-   asymptomatic men >20 y/o	         			*Ann Intern Med* 1990
- Diabetes Mellitus, Type 2 			$70,000		CDC C-E Study Grp.
-   fasting plasma glucose, adults >25 y/o			*JAMA* 1998
- Colon cancer 				$57,700		Frazier
-   FOBT + SIG q5y, adults 50–85 y/o			*JAMA* 2000
- Breast cancer				$57,500		Salzmann
-   annual mammogram, women 50–69 y/o 		             	*Ann Intern Med* 1997
- HIV 					$50,000	   	Paltiel
-   routine, rapid testing in health settings* **	**	**	**Ann Intern Med* 2006

**Notes:**
This table shows the cost-effectiveness ratios for other non-HIV screening programs in the US.  At $50,000/QALY gained, HIV screening is more cost-effective than other screening programs currently considered standard, including screening for breast cancer, colon cancer,  diabetes and hypertension

## Cost-effectiveness: Common Misconception #2

- If an intervention is cost-effective, providers should be willing to pay for it.

## Cost-effectiveness does not address the question of who should pay

- Cost-effectiveness analysis is typically performed from a societal perspective
- Accounts for all costs and benefits, regardless       of who incurs or enjoys them.
*Cost-effective* from the societal perspective does not imply *cost-effective* from the hospital (or individual or provider) perspective.

## Cost-effectiveness: Common Misconception #3

- Cost-effectiveness geeks like Paltiel
- think they have the right answer. *

- *  This may not be a misconception.

## C-E: Only one of many criteria for judging the appropriateness of screening

- 1) 	Important health problem.
- 2) 	Natural history well understood.
- 3)	Detectable early stage.
- 4) 	More benefit from early treatment.
- 5) 	Acceptable test.
- 6) 	Intervals for repeating the test determined.
- 7) 	Adequate health service provision made for the extra clinical workload resulting from screening.
- 8) 	Physical/psychological risks less than benefits.
- 9) 	**Costs balanced against the benefits.**
- 	Wilson JM, Jungner G. *Principles and practice of screening for disease.* Geneva: World Health Organization, 1968.

## Common misconceptions about                cost-effectiveness analysis
Findings from recent evaluations
Findings on the survival benefits of AIDS treatments in the United States

- Findings from recent evaluations
- Findings on the survival benefits of AIDS treatments in the United States

- Road Map

## Acknowledgments

- Rochelle Walensky, MD, MPH
- Bruce Schackman, PhD,
- George Seage, DSc, MPH
- Sue Goldie, MD
- Milton Weinstein, PhD
- Douglas Owens, MD
- Gillian Sanders, PhD
- Elena Losina, PhD
- Kenneth Freedberg, MD, MSc

- NIDA Grant R01-DA015612
*Making Better Decisions: Policy Modeling for AIDS & Drug Abuse*
- Project Officer: Peter Hartsock, PhD

## A model-based approach*

- Computer simulations of the natural history and detection of HIV disease.
- Capture effects of CD4, HIV-RNA, OI incidence, and the impact of ART and other therapies.
- Assemble data from observational cohorts, clinical trials, cost surveys, and other published sources.
- Project outcomes: life expectancy, quality-adjusted life-expectancy, cost, cost-effectiveness.

- * So many assumptions/limitations, so little time...

**Notes:**
We used an existing computer simulation model of HIV infection and treatment and updated this model to include HIV screening and symptom detection.  The disease model uses data from large cohorts like the Multicenter AIDS cohort study, and from clinical trials of antiretroviral efficacy, including Dupont 006.  Cost data are updated from the AIDS cost and services utilization survey.  The model includes prophylaxis and therapy for PCP, toxoplasmosis, MAC, CMV and fungal infections. The Model allows for comparisons in clinical  outcomes cost, and cost-effectiveness of alternative treatment and screening strategies.

## 					        C-E ratio	
Screening Program		       ($/QALY)		Reference

Inpatient antibody testing		         $38,600 	   Walensky Am J Med 2005

“Routine” standard antibody testing
 in populations with prevalence = 1%       $41,700   	   Sanders NEJM 2005

“One-time” rapid antibody testing
 in populations with  prevalence = 0.2%   $50,000	   Paltiel Ann Intern Med 2006

Standard antibody test, every 5 years,
 in high-risk populations		         $50,000	   Paltiel NEJM 2005

- 					        C-E ratio
- Screening Program		       ($/QALY)		Reference
- Inpatient antibody testing		         $38,600 	   Walensky *Am J Med* 2005
- “Routine” standard antibody testing
-  in populations with prevalence = 1%       $41,700   	   Sanders *NEJM* 2005
- “One-time” rapid antibody testing
-  in populations with  prevalence = 0.2%   $50,000	   Paltiel *Ann Intern Med* 2006
- Standard antibody test, every 5 years,
-  in high-risk populations		         $50,000	   Paltiel *NEJM* 2005

- Routine HIV screening is cost effective, even in very low-risk populations

- Routine HIV screening is cost effective, even in very low-risk populations

## Why HIV screening is cost-effective

## It changes the mechanism of HIV detection

- It changes the mechanism of HIV detection

## 2. It results in earlier detection of illness

- Paltiel, *NEJM,* 2005

## 3. Earlier detection improves survival

- Paltiel, *NEJM,* 2005

## 4. And while it does increase costs...

- Paltiel, *NEJM,* 2005

## 4. ...it’s worth it!

- Paltiel, *NEJM,* 2005

## Insensitivity to both undetected prevalence and the cost of the test

- $30,000

- $40,000

- $50,000

- $60,000

- $70,000

- $80,000

- $90,000

- 0.1

- 1

- 10

- 100

- Prevalence (%)

- CE Ratio ($/QALY)

- Test Cost = $104

- Test Cost = $52

-   Baseline: Test Cost = $26

-  Test Cost = $1

- Walensky, *Am J Med* 2005

**Notes:**
This analysis shows the impact of cost of the HIV screening test.  The prevalence of undiagnosed HIV infection is on the horizontal axis and the cost-effectiveness ratio on the vertical axis.  At test costs of $26, the cost-effectiveness ratio changes little until the prevalences approaches 0.1% on the left.  The plateau effect of about $36,000/QALY at any prevalence above 1% to the right  is driven by the costs of caring for HIV-infected individuals in the US and is only minimally affected by the comparatively inexpensive costs of testing.Alternative costs of testing are shown on this graph.  Doubling the baseline costs from $26 to $52 as shown in orange triangles, or even quadrupling this cost to $104 shown in red circles, all yield cost-effectiveness ratios under $50,000/QALY at undiagnosed prevalence of HIV of  0.5% and under $90,000/QALY at undiagnosed HIV prevalences of 0.1%.  

## What about the secondary transmission benefits of HIV screening?

- Paltiel, *Ann Int Med,* 2006

- Population-level effects are comparatively small.
- The principal costs and benefits of HIV screening are those that accrue to the infected individual.
- Individual-level outcomes alone justify expansion of HIV screening in all but the lowest-risk populations.

## Implicit Assumption:Adequate linkage to lifesaving care

- 1) 	Important health problem.
- 2) 	Natural history well understood.
- 3)	Detectable early stage.
- 4) 	More benefit from early treatment.
- 5) 	Acceptable test.
- 6) 	Intervals for repeating the test determined.
- 7) 	**Adequate health service provision made for the extra clinical workload resulting from screening.**
- 8) 	Physical/psychological risks less than benefits.
- 9) 	Costs balanced against the benefits.
- 	Wilson JM, Jungner G. *Principles and practice of screening for disease.* Geneva: World Health Organization, 1968.

## Common misconceptions about                cost-effectiveness analysis
Findings from recent evaluations
Findings on the survival benefits of AIDS treatments in the United States

- Findings from recent evaluations
- Findings on the survival benefits of AIDS treatments in the United States

- Road Map

## Why bother testing?

- Walensky, *J Infect Dis* 2006

## Timeline of Major HIV Interventions 

- Walensky, *J Infect Dis* 2006

**Notes:**
This figure depicts the timeline of major HIV interventions we considered and when they became standard of care in the US.  We include prophylaxis for Pneumocystis carinii pneumonia, starting to 1989 and add Mycobacterium avium complex, or MAC, prophylaxis starting in 1993.  Prevention of mother to child transmission with AZT began in 1994. 1996 marks the beginning of highly active antiretroviral therapy.  We characterize the improvements in ART efficacy over time by dividing ART into 4 eras, beginning in 1996, 1998, 2000 and 2003. 

## AIDS Survival by Era

- Walensky, *J Infect Dis* 2006

**Notes:**
This figure shows model-based survival curves for patients diagnosed in the first year of each of the six treatment eras (1989, 1993, 1996, 1998, 2000, 2003) and untreated disease, shown in gray.  The area between the curves illustrates the improvement in AIDS-associated survival in the US over time.  Median survival was 1.7 years for the PCP era shown in yellow, 7.5 years for ART 1 shown in light blue, and 14.1 years for ART 4, the upper most curve shown in pink. 

## Survival Gains Compared withVarious Disease Interventions

- Walensky, *J Infect Dis* 2006

**Notes:**
This slide shows the per person survival gains with various disease interventions in the US.  The vertical axis is now in months.  
Survival gains for non-small-cell lung cancer related chemotherapy, adjuvant chemotherapy for breast cancer, treatment during and after an acute myocardial infarction, and bone marrow transplantation for relapsed non-Hodgkins lymphoma are shown in yellow.  When not available directly from the literature, these LE estimates were synthesized from a compilation of numerous sources.  In comparison, in orange, we see interventions in AIDS care.   While OI prophylaxis led to a modest 3-month benefit, antiretroviral therapy has resulted in 160 months of survival gain.  That is, it has increased the per person life expectancy of patients with AIDS by 13 years.
Sources:
Survival from thrombolytics during an MI: (Wright and Weinstein NEJM 1998 cite a 1992 paper from European Heart Journal 
1)  P(MI survival): Rosamond W et al Trends in the Incidence of MI and in Mortality due to coronary Heart Disease, 1987, 1994. NEJM 1998;339:861-7.
LE LE gains from angioplasty: Kuntz et al, Cost-effectiveness of routine coronary angiography after acute MI.  Circulation. 1996;94:957-965. 
1)      LE gains from beta-blockers: Phillips K et al Health and economic benefits of increased b-blocker use following an MI.  JAMA 2000;284:2748-2745.
LE gains from clopidogrel: Weintraub et al. Long-term cost-effectivenss of clopidogrel given for up to one year in patients with acute coronary syndromes without ST elevation.  Journal of the America College of Cardiology.  2005;45:838-45). 

## “A celebration with challenges”                              – Sten Vermund

- At least 3 million years of life have been saved in the US as a direct result of AIDS patient care
- An additional 740,000 years of life might have been saved, had all patients with AIDS received appropriate treatment on diagnosis.

## Not every one has shared equally in the gains

- Losina, *CROI* 2006

**Notes:**
This slide illustrates combined effect of late presentation and premature discontinuation stratified by gender and race/ethnicity.  Yellow segments represent the contribution of late initiation and orange segments represent contribution of premature discontinuation. Compared to white women for whom additional years of life lost due to late presentation and premature discontinuation were estimated as 3.7 years on average, other sub-populations experienced even higher life expectancy losses.  They ranged from 0.5 year higher for white men (4.2 years) to about 2.7 years higher for Hispanic women for whom estimated additional life expectancy losses reached 6.4 years on average.  The combined impact of late presentation and early discontinuation also resulted in higher total survival losses for racial/ethnic minorities compared to whites.

## Conclusions

- HIV screening delivers better value than many other diagnostic tests in routine use.
- Our findings support the CDC recommendation of routine HIV testing for all adults in all health care setting in the US.
- Not all Americans share equally in the huge survival benefits of AIDS therapy. Women from racial and ethnic minorities are at particular risk.
- Effective HIV testing programs must be accompanied by a simultaneous commitment to improved linkage to care and to paying for that care.

**Notes:**

We have made great strides in HIV care. The survival gap between HIV-infected and normal life expectancy continues to narrow. But we have more work to do.  Survival losses due to suboptimal access are entirely preventable.  Today.  We can achieve earlier presentation and retention in care for all HIV-infected persons, with particular focus on women from racial and ethnic minorities. Our findings present strong evidence in support of expanded, routine HIV testing as a practical means to earlier diagnosis.