Task_Order_1.pdf

TASK ORDER #1: Analysis of older populations with HIV

STATEMENT OF WORK

I. Background:

The dynamic, compartmental HIV Optimization and Prevention Economics

(HOPE) model, developed by the Prevention Modeling and Economics Team

(PMET) in the Centers for Disease Control and Prevention (CDC), Division of

HIV/AIDS Prevention (DHAP), simulates the sexually active U.S. population aged 13 to 64 beginning in 2006. The population is stratified into 195 subpopulations by transmission group (gay, bisexual, and other men who have sex with men [collectively referred to as MSM], persons who inject drugs [PWID], or sexually active heterosexuals); sex (male or female); race/ethnicity (black, Hispanic/Latino, or white/other racial-ethnic groups combined, of which whites comprised 89%); age group (13–17, 18–24, 25–34, 35–44, or 45–64 years of age);

male circumcision status (circumcised or uncircumcised); and HIV risk level (low or high).

The model distributes each of the subpopulations across 25 compartments. All

HIV-uninfected individuals are in two susceptible model compartments, stratified by use of pre-exposure prophylaxis. Persons living with HIV are distributed among 23 compartments defined by disease progression and continuum-of-care stage. The model captures five HIV disease stages: acute infection, infection with

CD4 count >500 [cells/mm3], CD4 count of 350 to 500, CD4 count of 200 to 350, and CD4 count <200 (i.e., AIDS). In addition to disease stages, the model captures five continuum-of-care steps: unaware of infection; aware, but not linked to HIV care; linked to HIV care, but not on antiretroviral therapy (ART); on ART, but not with viral load suppression (VLS); or VLS, which assumes people are in care and on ART.

The total population, both HIV-uninfected and infected, transitions among the 25 compartments and moves into and out of the model via aging and death. The model uses differential equations to represent the progression of the HIV-uninfected and HIV-infected populations among compartments.

II. Purpose:

The purpose of this task order is to extend the model to calibrate to and project

HIV incidence and prevalence in older populations by generating additional age-related stratifications for people living with HIV who are 45 and older, and incorporating the population aged 65 and older.

III. Scope of Work:

Independently, and not as an agent of the government, the Contractor will furnish all the necessary personnel, facilities, supplies, and equipment required to extend the model to this older age group and to estimate HIV incidence and prevalence among these persons. All analyses and models under this task will become the property of the Government.

IV. Specific Tasks:

The Contractor shall perform the following tasks:

(a) Conduct a review of the HOPE model to validate the current parameters and data used in the model.

(b) Review the literature and identify the best and most recent detailed data on the current population aged 45 to 54, 55 to 64, and 65 and older, the incidence and prevalence of HIV among these persons, and the HIV risk behaviors relevant to those ages.

(c) Review the literature to determine what changes in death rates need to be incorporated for the older population to account for multiple comorbidities of age-related non-communicable diseases.

(d) Update the code and the data of the model to include the stratification of age

45 to 54, 55 to 64, and those aged 65 and older.

(e) Generate estimates of HIV incidence and prevalence among these populations.

(f) For inputs for which data were limited or uncertain, obtain input values through a calibration process by varying those values within expected bounds.

The bounds are to be informed by the literature, data, or expert opinion. These inputs will be calibrated so that outcomes match surveillance data for one or multiple time points.

(g) Use the elementary effects method, a one-at-a-time sensitivity analysis to identify inputs to which a model’s outcomes are most sensitive, to select a smaller number of inputs for examination in further sensitivity or uncertainty analyses. The elementary effects method measures the effects of changes in each input as both that input and all other inputs take on a variety of values.

As a result, it is helpful for measuring the sensitivity of outcomes to inputs in non-linear models with a large number of inputs, such as this one.

(h) To consider the uncertainty of HIV incidence among the population aged 45 and older due to the values of the calibrated parameters, run the model using multiple additional sets of values for those inputs that, like the set used in the base case analysis, approximated the targeted surveillance measures. Report the range of incidence estimates among the population aged 65 and older across those runs to assess the robustness of the findings.

(i) Develop the methods and results sections of a first draft of a manuscript that incorporates the incidence and prevalence results, the sensitivity analysis, and the uncertainty analysis.

(j) Prepare manuscript for publication in a peer-reviewed journal. Respond to requests for revisions until the manuscript is published.

(k) Provide technical assistance to scientists within PMET on computer codes, analyses, and manuscripts.

V. Reporting Requirements:

The Contractor shall furnish monthly progress reports in the specified electronic format detailing current status of each specific task required under this task order.

The report shall be narrative in form and shall include a summary of progress toward completion of each and any problems encountered to date, including the

Contractor’s assessment of the specific impact of such problems on scheduled date of completion of milestones. Contractor will have biweekly (at a minimum) telephone calls with technical monitor to discuss progress, problems and solutions.

VI. Period of Performance: 12 months from date of task order award.

VII. Deliverables:

The Contractor shall furnish the CDC Project Officer and Technical Monitor the following items in the quantities and during the time periods indicated. All documents to be in Microsoft Word© or Excel© format, unless alternative formats are approved in advance by CDC.

1. The Contractor shall update the HOPE model to include the code and data necessary to estimate HIV incidence and prevalence from 2016 to 2030 among those aged 45-54, 55-64, and 65 years and older. All input data and assumptions made will be approved by the Government.

2. The Contractor shall submit a draft manuscript summarizing the results of the incidence and prevalence estimation and the sensitivity and uncertainty analyses. The Contractor shall respond to revision requests by PMET staff until the manuscript has received final DHAP approval and clearance.

ITEM DESCRIPTION COPIES DUE DATE

1 Progress reports. Monthly reports include: work done in the preceding 2 weeks;

problems and corrective actions; expenditure report

1 electronic copy to technical monitor.

Bi-weekly, commencing 14 days after the contract award, and expenditure estimate for next 2-week period.

until 12 months after.

2 Kick-off meeting in Atlanta 1 electronic copy of synopsis of meeting to technical monitor

Within 1 month of award of contract.

3 Review existing HOPE model parameters and data.

1 electronic copy to technical monitor of suggested parameters that require updates..

Within 2 months of award of contract.

4 Review literature on incidence and prevalence of

HIV among those aged 45 years and older and on death rates in this population.

Review literature on HIV-related risk behaviors in these age groups. Recommend data inputs based on most relevant and sound scientific data.

1 electronic copy of summary findings and recommendations to technical monitor.

Within 4 months of award of contract.

5 Update code and data and recalibrate the model.

1 electronic copy of summary findings to technical monitor to include final calibration sets and calibration results.

Within 6 months of award of contract.

6 Generate HIV incidence and prevalence estimates over time, among selected older age groups.

1 electronic copy of all results to technical monitor.

Within 7 months of award of contract.

7 Perform sensitivity and uncertainty analyses.

1 electronic copy of all results to technical monitor.

Within 8 months of award of contract.

8 Submit draft manuscript:

methods and results

1 electronic copy of all results to technical monitor

Within 9 months of award of contract.

9 Prepare manuscript for publication in a peer-reviewed journal. Respond to requests for revisions until the manuscript is published.

Electronic drafts as requested to technical monitor.

Within 12 months of award of contract.

10 Updated User’s Guide, and

Updated Technical Appendix

Within 9 months of award of contract.

11 Technical assistance to team members

1 electronic copy to technical monitor summarizing Qs and As.

Within 12 months of award of contract.