HIRI-MSM HIV incidence risk index

HIRI-MSM

Sum the published Smith 2012 seven-item HIV incidence risk index for MSM (age plus six prior-6-month behaviors, 0–47) and return at_or_above_10 when the total is ≥10.

LIVE $0.005 USDC GET /api/calc/hiri_msm

Markdown: /docs/hiri-msm.md · Canonical: https://magentlab.com/docs/hiri-msm

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Sum the published Smith 2012 seven-item HIV incidence risk index for MSM (age plus six prior-6-month behaviors, 0–47) and return at_or_above_10 when the total is ≥10.

When to use

When an agent needs the published Smith 2012 point total from caller-assigned counts and must not invent a diagnosis, a PrEP order, or a sexual history.

When not to use

Not a medical device. Not a diagnosis of HIV infection and not a PrEP, nPEP, or antiretroviral order.
Smith 2012 seven-item index only (age + six 6-month behaviors). Range 0–47. Published screening cutoff score ≥10. Not Menza 2009 and not the SexPro model.
Counts and flags are caller-assigned. magent does not take a sexual history or a substance-use history. No race field.
Keeps the HIV-positive partner count. Not a simplified 6-input website variant that drops that item or changes the published bands.
Age is 18–120. The paper listed <18 as 0 points; magent rejects age outside 18–120 as invalid_age.

Formula

HIRI-MSM = age + male_sex_partners_6mo + hiv_positive_male_partners_6mo + unprotected_receptive_anal_6mo + insertive_anal_hiv_positive_6mo + poppers_6mo + amphetamines_6mo; age 18-28 -> 8, 29-40 -> 5, 41-48 -> 2, >=49 -> 0; male partners 0-5 -> 0, 6-10 -> 4, >=11 -> 7; HIV-positive partners 0 -> 0, 1 -> 4, >=2 -> 8; unprotected receptive anal 0 -> 0, >=1 -> 10; insertive anal with HIV-positive partner 0-4 -> 0, >=5 -> 6; poppers true -> 3; amphetamines true -> 5; max 47; at_or_above_10 iff score>=10

Citation

Title: Development of a Clinical Screening Index Predictive of Incident HIV Infection Among Men Who Have Sex With Men in the United States
Authors: Smith DK, Pals SL, Herbst JH, Shinde S, Carey JW
Source: J Acquir Immune Defic Syndr. 2012;60(4):421-427
DOI: 10.1097/QAI.0b013e318256b2f6

Worked example

Lowest-risk row (older age, zero partners/acts, no poppers/amphetamines)

Given: age=55amphetamines_6mo=falsehiv_positive_male_partners_6mo=0insertive_anal_hiv_positive_6mo=0male_sex_partners_6mo=0poppers_6mo=falseunprotected_receptive_anal_6mo=0

Age 55 ≥49 → 0; male partners 0 → 0; HIV-positive partners 0 → 0
Unprotected receptive anal 0 → 0; insertive anal with HIV-positive partner 0 → 0; poppers false → 0; amphetamines false → 0
Score = 0 (published max 47); at_or_above_10 false (cutoff ≥10)

Cutoff ≥10 (one unprotected receptive anal act)

Given: age=55amphetamines_6mo=falsehiv_positive_male_partners_6mo=0insertive_anal_hiv_positive_6mo=0male_sex_partners_6mo=0poppers_6mo=falseunprotected_receptive_anal_6mo=1

Age 55 → 0; unprotected receptive anal ≥1 → 10; other items 0
Score = 10; at_or_above_10 true (cutoff ≥10). Not a diagnosis or PrEP order.

Also searched as

HIRI-MSM
HIV incidence risk index
Smith 2012 HIV risk index
MSM HIV screening index
HIV risk index for MSM
seven-item MSM HIV index

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/hiri_msm?age=55&male_sex_partners_6mo=0&hiv_positive_male_partners_6mo=0&unprotected_receptive_anal_6mo=0&insertive_anal_hiv_positive_6mo=0&poppers_6mo=false&amphetamines_6mo=false

Full URL: https://api.magentlab.com/api/calc/hiri_msm?age=55&male_sex_partners_6mo=0&hiv_positive_male_partners_6mo=0&unprotected_receptive_anal_6mo=0&insertive_anal_hiv_positive_6mo=0&poppers_6mo=false&amphetamines_6mo=false

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/hiri_msm?age=55&male_sex_partners_6mo=0&hiv_positive_male_partners_6mo=0&unprotected_receptive_anal_6mo=0&insertive_anal_hiv_positive_6mo=0&poppers_6mo=false&amphetamines_6mo=false"

Parameters

Name	Type	Required	Description
`age`	integer	required	Age in years (18-120). Smith 2012: 18-28 scores 8; 29-40 scores 5; 41-48 scores 2; ≥49 scores 0. Caller-assigned. magent does not take a sexual history.
`male_sex_partners_6mo`	integer	required	Caller-assigned number of male sex partners in the prior 6 months (0-500). Smith 2012: 0-5 scores 0; 6-10 scores 4; ≥11 scores 7.
`hiv_positive_male_partners_6mo`	integer	required	Caller-assigned number of HIV-positive male sex partners in the prior 6 months (0-500). Smith 2012: 0 scores 0; 1 scores 4; ≥2 scores 8. Do not drop this item.
`unprotected_receptive_anal_6mo`	integer	required	Caller-assigned times the person had unprotected receptive anal sex with a male partner of any HIV status in the prior 6 months (0-500). Smith 2012: 0 scores 0; ≥1 scores 10.
`insertive_anal_hiv_positive_6mo`	integer	required	Caller-assigned times the person had insertive anal sex with an HIV-positive male partner in the prior 6 months (0-500). Smith 2012: 0-4 scores 0; ≥5 scores 6.
`poppers_6mo`	boolean	required	Caller-assigned popper (amyl nitrate) use in the prior 6 months (Smith 2012). true or false. magent does not take a substance-use history.
`amphetamines_6mo`	boolean	required	Caller-assigned amphetamine use in the prior 6 months (Smith 2012). true or false. magent does not take a substance-use history.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/hiri_msm Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

1 to 25 items. Each item uses the same keys as the GET query parameters.
POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "age": "55",
      "amphetamines_6mo": "false",
      "hiv_positive_male_partners_6mo": "0",
      "insertive_anal_hiv_positive_6mo": "0",
      "male_sex_partners_6mo": "0",
      "poppers_6mo": "false",
      "unprotected_receptive_anal_6mo": "0"
    },
    {
      "age": "55",
      "amphetamines_6mo": "false",
      "hiv_positive_male_partners_6mo": "0",
      "insertive_anal_hiv_positive_6mo": "0",
      "male_sex_partners_6mo": "0",
      "poppers_6mo": "false",
      "unprotected_receptive_anal_6mo": "0"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/hiri_msm",
  "items": [
    {
      "components": [
        {
          "value": 55,
          "factor": "age",
          "points": 0,
          "present": false
        },
        {
          "value": 0,
          "factor": "male_sex_partners_6mo",
          "points": 0,
          "present": false
        },
        {
          "value": 0,
          "factor": "hiv_positive_male_partners_6mo",
          "points": 0,
          "present": false
        },
        {
          "value": 0,
          "factor": "unprotected_receptive_anal_6mo",
          "points": 0,
          "present": false
        },
        {
          "value": 0,
          "factor": "insertive_anal_hiv_positive_6mo",
          "points": 0,
          "present": false
        },
        {
          "factor": "poppers_6mo",
          "points": 0,
          "present": false
        },
        {
          "factor": "amphetamines_6mo",
          "points": 0,
          "present": false
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Smith DK, Pals SL, Herbst JH, Shinde S, Carey JW",
        "doi": "10.1097/QAI.0b013e318256b2f6",
        "id": "smith-dk-2012",
        "pmid": "22487585",
        "source": "J Acquir Immune Defic Syndr. 2012;60(4):421-427",
        "title": "Development of a Clinical Screening Index Predictive of Incident HIV Infection Among Men Who Have Sex With Men in the United States"
      },
      "formula": "hiri_msm",
      "formula_expression": "HIRI-MSM = age + male_sex_partners_6mo + hiv_positive_male_partners_6mo + unprotected_receptive_anal_6mo + insertive_anal_hiv_positive_6mo + poppers_6mo + amphetamines_6mo; age 18-28 -> 8, 29-40 -> 5, 41-48 -> 2, >=49 -> 0; male partners 0-5 -> 0, 6-10 -> 4, >=11 -> 7; HIV-positive partners 0 -> 0, 1 -> 4, >=2 -> 8; unprotected receptive anal 0 -> 0, >=1 -> 10; insertive anal with HIV-positive partner 0-4 -> 0, >=5 -> 6; poppers true -> 3; amphetamines true -> 5; max 47; at_or_above_10 iff score>=10",
      "max_score": 47,
      "score": 0,
      "age_years": 55,
      "at_or_above_10": false,
      "hiv_positive_male_partners_6mo": 0,
      "insertive_anal_hiv_positive_6mo": 0,
      "male_sex_partners_6mo": 0,
      "unprotected_receptive_anal_6mo": 0
    },
    {
      "components": [
        {
          "value": 55,
          "factor": "age",
          "points": 0,
          "present": false
        },
        {
          "value": 0,
          "factor": "male_sex_partners_6mo",
          "points": 0,
          "present": false
        },
        {
          "value": 0,
          "factor": "hiv_positive_male_partners_6mo",
          "points": 0,
          "present": false
        },
        {
          "value": 0,
          "factor": "unprotected_receptive_anal_6mo",
          "points": 0,
          "present": false
        },
        {
          "value": 0,
          "factor": "insertive_anal_hiv_positive_6mo",
          "points": 0,
          "present": false
        },
        {
          "factor": "poppers_6mo",
          "points": 0,
          "present": false
        },
        {
          "factor": "amphetamines_6mo",
          "points": 0,
          "present": false
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Smith DK, Pals SL, Herbst JH, Shinde S, Carey JW",
        "doi": "10.1097/QAI.0b013e318256b2f6",
        "id": "smith-dk-2012",
        "pmid": "22487585",
        "source": "J Acquir Immune Defic Syndr. 2012;60(4):421-427",
        "title": "Development of a Clinical Screening Index Predictive of Incident HIV Infection Among Men Who Have Sex With Men in the United States"
      },
      "formula": "hiri_msm",
      "formula_expression": "HIRI-MSM = age + male_sex_partners_6mo + hiv_positive_male_partners_6mo + unprotected_receptive_anal_6mo + insertive_anal_hiv_positive_6mo + poppers_6mo + amphetamines_6mo; age 18-28 -> 8, 29-40 -> 5, 41-48 -> 2, >=49 -> 0; male partners 0-5 -> 0, 6-10 -> 4, >=11 -> 7; HIV-positive partners 0 -> 0, 1 -> 4, >=2 -> 8; unprotected receptive anal 0 -> 0, >=1 -> 10; insertive anal with HIV-positive partner 0-4 -> 0, >=5 -> 6; poppers true -> 3; amphetamines true -> 5; max 47; at_or_above_10 iff score>=10",
      "max_score": 47,
      "score": 0,
      "age_years": 55,
      "at_or_above_10": false,
      "hiv_positive_male_partners_6mo": 0,
      "insertive_anal_hiv_positive_6mo": 0,
      "male_sex_partners_6mo": 0,
      "unprotected_receptive_anal_6mo": 0
    }
  ]
}

Response

Field	Type	Description
`formula`	string	hiri_msm
`formula_expression`	string	Exact expression used
`score`	integer	Smith 2012 HIRI-MSM points 0-47
`max_score`	integer	47
`at_or_above_10`	boolean	true when score ≥10, the published Smith 2012 screening cutoff. Not a diagnosis or PrEP order.
`age_years`	integer	Age in years used for the age band
`male_sex_partners_6mo`	integer	Caller-assigned male sex partners in the prior 6 months
`hiv_positive_male_partners_6mo`	integer	Caller-assigned HIV-positive male partners in the prior 6 months
`unprotected_receptive_anal_6mo`	integer	Caller-assigned unprotected receptive anal acts in the prior 6 months
`insertive_anal_hiv_positive_6mo`	integer	Caller-assigned insertive anal acts with an HIV-positive partner in the prior 6 months
`components`	array	Per-item points
`citation`	object	Smith et al. JAIDS 2012 citation
`disclaimer`	string	Not-a-device notice

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "components": [
    {
      "value": 55,
      "factor": "age",
      "points": 0,
      "present": false
    },
    {
      "value": 0,
      "factor": "male_sex_partners_6mo",
      "points": 0,
      "present": false
    },
    {
      "value": 0,
      "factor": "hiv_positive_male_partners_6mo",
      "points": 0,
      "present": false
    },
    {
      "value": 0,
      "factor": "unprotected_receptive_anal_6mo",
      "points": 0,
      "present": false
    },
    {
      "value": 0,
      "factor": "insertive_anal_hiv_positive_6mo",
      "points": 0,
      "present": false
    },
    {
      "factor": "poppers_6mo",
      "points": 0,
      "present": false
    },
    {
      "factor": "amphetamines_6mo",
      "points": 0,
      "present": false
    }
  ],
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Smith DK, Pals SL, Herbst JH, Shinde S, Carey JW",
    "doi": "10.1097/QAI.0b013e318256b2f6",
    "id": "smith-dk-2012",
    "pmid": "22487585",
    "source": "J Acquir Immune Defic Syndr. 2012;60(4):421-427",
    "title": "Development of a Clinical Screening Index Predictive of Incident HIV Infection Among Men Who Have Sex With Men in the United States"
  },
  "formula": "hiri_msm",
  "formula_expression": "HIRI-MSM = age + male_sex_partners_6mo + hiv_positive_male_partners_6mo + unprotected_receptive_anal_6mo + insertive_anal_hiv_positive_6mo + poppers_6mo + amphetamines_6mo; age 18-28 -> 8, 29-40 -> 5, 41-48 -> 2, >=49 -> 0; male partners 0-5 -> 0, 6-10 -> 4, >=11 -> 7; HIV-positive partners 0 -> 0, 1 -> 4, >=2 -> 8; unprotected receptive anal 0 -> 0, >=1 -> 10; insertive anal with HIV-positive partner 0-4 -> 0, >=5 -> 6; poppers true -> 3; amphetamines true -> 5; max 47; at_or_above_10 iff score>=10",
  "max_score": 47,
  "score": 0,
  "age_years": 55,
  "at_or_above_10": false,
  "hiv_positive_male_partners_6mo": 0,
  "insertive_anal_hiv_positive_6mo": 0,
  "male_sex_partners_6mo": 0,
  "unprotected_receptive_anal_6mo": 0
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP	Code	When
400	`invalid_age`	age must be an integer from 18 to 120 Returned before settlement; you are not charged.
400	`invalid_sex_partner_count`	male_sex_partners_6mo must be an integer from 0 to 500 (Smith 2012 HIRI-MSM male partners in the prior 6 months). Returned before settlement; you are not charged.
400	`invalid_anal_act_count`	unprotected_receptive_anal_6mo and insertive_anal_hiv_positive_6mo must each be an integer from 0 to 500 (Smith 2012 HIRI-MSM act counts in the prior 6 months). Returned before settlement; you are not charged.
400	`invalid_flag`	boolean clinical flags must be true or false Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

Menza — Sum the four Menza 2009 caller-assigned flags and return the 0–19 point total.
CAGE — Sum the four Ewing 1984 CAGE items and return whether two or more answers are affirmative.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
Execution is timeout-bounded and concurrency-capped.
Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.