Rotgar

Rotgar Research

Google and AI Source Overlap Across 12 Medical Niches

A descriptive US benchmark of explicit ChatGPT and Gemini citations against paired Google organic Top 20 results across 12 medical niches.

By Evgeniy Yudin, Founder and Strategy Lead Methodology reviewed by Boris Teplyakov, SEO Lead Published Version 1.0 US English

Boris Teplyakov reviewed the research methodology as SEO Lead. This was not a medical or legal subject-matter review of the questions, answers or cited sources.

Read the findingsReview the methodology

Direct answer

Do ChatGPT and Gemini cite the same medical sources as Google?

Across the same 322 eligible tasks, exact URL overlap was 13.6% for ChatGPT and 53.9% for Gemini. At domain level, overlap was 39.8% and 68.6% across the same 322 eligible tasks. In this like-for-like comparison, Gemini overlap was +40.3 percentage points higher at exact-URL level and +28.8 percentage points higher at registrable-domain level. This is a descriptive source-overlap benchmark; it does not measure accuracy, source quality, rankings, traffic, leads or patient outcomes.

US-English observation window: . Results describe explicit source overlap only.

Study at a glance

Questions analyzed
432
Across 12 medical niches
ChatGPT exact URL overlap
13.6%
39.8% at domain level · URL n=322; domain n=322
Gemini exact URL overlap
53.9%
68.6% at domain level · URL n=322; domain n=322
ChatGPT–Gemini domain similarity
8.2%
Mean task-level Jaccard · n=336

Practical definitions

Questions marketers ask about this study

Short answers for medical marketers; the full evidence and limitations remain below.

Do ChatGPT and Gemini cite the same medical sources as Google?

Across the same 322 eligible tasks, exact URL overlap was 13.6% for ChatGPT and 53.9% for Gemini. Domain overlap was 39.8% and 68.6% across 322 same-task observations. In this like-for-like comparison, Gemini overlap was +40.3 percentage points higher at exact-URL level and +28.8 percentage points higher at registrable-domain level. This is a descriptive source-overlap benchmark; it does not measure accuracy, source quality, rankings, traffic, leads or patient outcomes.

What is the difference between URL and domain overlap?

Exact URL overlap requires the same normalized page to appear in both source sets. Domain overlap is broader: two different pages can count as a match when they belong to the same registrable domain.

Does this study measure accuracy or rankings?

No. It measures overlap among explicitly exposed sources. It does not establish answer accuracy, source quality, rankings, traffic, leads or patient outcomes.

Can the published data be downloaded?

Yes. The download section provides XLSX, CSV, JSON, BibTeX, CFF, SVG files with their labels and study context, without an email gate.

Browse the evidence

Findings by niche

Each result below is a static, deep-linkable summary of the same frozen study. Cross-niche differences are descriptive and should not be treated as rankings.

Dentistry

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Dentistry questions?

Across 36 US-English Dentistry questions, the primary eligible sets contained 23 ChatGPT task cells and 18 Gemini task cells. Exact-URL overlap was 7.1% and 53.5%, respectively; registrable-domain overlap was 19.3% and 56.7%. Mean ChatGPT–Gemini citation-domain Jaccard was 4.8% across 28 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
7.1% URL
19.3% domain · n=23
Gemini
53.5% URL
56.7% domain · n=18
AI-domain similarity
4.8%
Mean Jaccard · n=28

Fertility

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Fertility questions?

Across 36 US-English Fertility questions, the primary eligible sets contained 30 ChatGPT task cells and 23 Gemini task cells. Exact-URL overlap was 23.6% and 62.3%, respectively; registrable-domain overlap was 41.8% and 84.5%. Mean ChatGPT–Gemini citation-domain Jaccard was 8.2% across 27 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
23.6% URL
41.8% domain · n=30
Gemini
62.3% URL
84.5% domain · n=23
AI-domain similarity
8.2%
Mean Jaccard · n=27

Dermatology

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Dermatology questions?

Across 36 US-English Dermatology questions, the primary eligible sets contained 36 ChatGPT task cells and 30 Gemini task cells. Exact-URL overlap was 19.5% and 53.3%, respectively; registrable-domain overlap was 55.4% and 65.7%. Mean ChatGPT–Gemini citation-domain Jaccard was 11.0% across 30 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
19.5% URL
55.4% domain · n=36
Gemini
53.3% URL
65.7% domain · n=30
AI-domain similarity
11.0%
Mean Jaccard · n=30

Plastic Surgery

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Plastic Surgery questions?

Across 36 US-English Plastic Surgery questions, the primary eligible sets contained 36 ChatGPT task cells and 29 Gemini task cells. Exact-URL overlap was 15.7% and 49.2%, respectively; registrable-domain overlap was 44.2% and 66.9%. Mean ChatGPT–Gemini citation-domain Jaccard was 8.3% across 29 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
15.7% URL
44.2% domain · n=36
Gemini
49.2% URL
66.9% domain · n=29
AI-domain similarity
8.3%
Mean Jaccard · n=29

Aesthetic Medicine & Medspa

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Aesthetic Medicine & Medspa questions?

Across 36 US-English Aesthetic Medicine & Medspa questions, the primary eligible sets contained 36 ChatGPT task cells and 27 Gemini task cells. Exact-URL overlap was 11.9% and 45.9%, respectively; registrable-domain overlap was 31.1% and 52.5%. Mean ChatGPT–Gemini citation-domain Jaccard was 3.1% across 27 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
11.9% URL
31.1% domain · n=36
Gemini
45.9% URL
52.5% domain · n=27
AI-domain similarity
3.1%
Mean Jaccard · n=27

Ophthalmology

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Ophthalmology questions?

Across 36 US-English Ophthalmology questions, the primary eligible sets contained 36 ChatGPT task cells and 26 Gemini task cells. Exact-URL overlap was 14.4% and 59.3%, respectively; registrable-domain overlap was 39.6% and 76.0%. Mean ChatGPT–Gemini citation-domain Jaccard was 9.7% across 26 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
14.4% URL
39.6% domain · n=36
Gemini
59.3% URL
76.0% domain · n=26
AI-domain similarity
9.7%
Mean Jaccard · n=26

Orthopedics

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Orthopedics questions?

Across 36 US-English Orthopedics questions, the primary eligible sets contained 36 ChatGPT task cells and 27 Gemini task cells. Exact-URL overlap was 12.9% and 56.1%, respectively; registrable-domain overlap was 30.9% and 75.0%. Mean ChatGPT–Gemini citation-domain Jaccard was 9.7% across 27 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
12.9% URL
30.9% domain · n=36
Gemini
56.1% URL
75.0% domain · n=27
AI-domain similarity
9.7%
Mean Jaccard · n=27

Behavioral Health

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Behavioral Health questions?

Across 36 US-English Behavioral Health questions, the primary eligible sets contained 36 ChatGPT task cells and 29 Gemini task cells. Exact-URL overlap was 5.1% and 44.9%, respectively; registrable-domain overlap was 40.4% and 55.3%. Mean ChatGPT–Gemini citation-domain Jaccard was 5.2% across 29 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
5.1% URL
40.4% domain · n=36
Gemini
44.9% URL
55.3% domain · n=29
AI-domain similarity
5.2%
Mean Jaccard · n=29

Addiction Treatment

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Addiction Treatment questions?

Across 36 US-English Addiction Treatment questions, the primary eligible sets contained 36 ChatGPT task cells and 26 Gemini task cells. Exact-URL overlap was 11.2% and 52.4%, respectively; registrable-domain overlap was 37.5% and 66.7%. Mean ChatGPT–Gemini citation-domain Jaccard was 4.5% across 26 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
11.2% URL
37.5% domain · n=36
Gemini
52.4% URL
66.7% domain · n=26
AI-domain similarity
4.5%
Mean Jaccard · n=26

Bariatrics

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Bariatrics questions?

Across 36 US-English Bariatrics questions, the primary eligible sets contained 36 ChatGPT task cells and 28 Gemini task cells. Exact-URL overlap was 10.4% and 51.2%, respectively; registrable-domain overlap was 48.7% and 68.5%. Mean ChatGPT–Gemini citation-domain Jaccard was 16.3% across 28 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
10.4% URL
48.7% domain · n=36
Gemini
51.2% URL
68.5% domain · n=28
AI-domain similarity
16.3%
Mean Jaccard · n=28

Urgent Care

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Urgent Care questions?

Across 36 US-English Urgent Care questions, the primary eligible sets contained 36 ChatGPT task cells and 27 Gemini task cells. Exact-URL overlap was 9.1% and 52.4%, respectively; registrable-domain overlap was 33.9% and 67.9%. Mean ChatGPT–Gemini citation-domain Jaccard was 7.9% across 27 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
9.1% URL
33.9% domain · n=36
Gemini
52.4% URL
67.9% domain · n=27
AI-domain similarity
7.9%
Mean Jaccard · n=27

Medical Imaging

How much did ChatGPT and Gemini sources overlap with Google's Top 20 for Medical Imaging questions?

Across 36 US-English Medical Imaging questions, the primary eligible sets contained 36 ChatGPT task cells and 32 Gemini task cells. Exact-URL overlap was 14.1% and 65.9%, respectively; registrable-domain overlap was 50.6% and 84.3%. Mean ChatGPT–Gemini citation-domain Jaccard was 9.3% across 32 eligible tasks. These August 7, 2026 observations describe source coincidence, not accuracy, source quality, rankings, traffic, leads or patient outcomes.

ChatGPT
14.1% URL
50.6% domain · n=36
Gemini
65.9% URL
84.3% domain · n=32
AI-domain similarity
9.3%
Mean Jaccard · n=32

How to read this study

A source-overlap benchmark, not a performance claim

Exact overlap only

This study measures exact URL and registrable-domain overlap. It does not measure Google AI Overviews or establish answer accuracy, source authority, rankings, traffic, leads, matters or patient outcomes.

Descriptive niche comparisons

The original four niches and 16-niche extension were collected in different windows and through live versus Standard queue endpoints. Cross-niche differences are descriptive.

DataForSEO surfaces

Google, ChatGPT and Gemini observations came from DataForSEO surfaces, not repeated logged-in consumer interface sessions.

Executive Summary

  • Exact URL coverage. Across 12 included niches, vertical-level ChatGPT estimates ranged from 5.1% to 23.6% and Gemini estimates ranged from 44.9% to 65.9%. Exact estimates, 95% intervals, and denominators are in the chart and evidence table. These are primary task-macro estimates conditional on an eligible citation-bearing AI cell and a complete paired Google Top 20. Primary estimates include only eligible paired Google Top 20 captures; exact eligible denominators are shown for every estimate.
  • Registrable-domain coverage. Across the same niches, ChatGPT registrable-domain estimates ranged from 19.3% to 55.4% and Gemini estimates ranged from 52.5% to 84.5%. Domain matching uses the analyzer's registrable-domain key rather than a simple host comparison. The two surfaces have different eligible task sets, so side-by-side values are not a paired-platform effect estimate. On common support across the included verticals, URL coverage was ChatGPT 13.6% versus Gemini 53.9% (Gemini minus ChatGPT +40.3 pp; n=322 tasks), and domain coverage was 39.8% versus 68.6% (difference +28.8 pp; n=322). These common-support differences are descriptive.
  • ChatGPT–Gemini citation-domain similarity. Across the included niches, mean task-level domain Jaccard ranged from 3.1% to 16.3%; exact niche denominators are shown with the chart.

Prior work and this study's scope

An Ahrefs study published August 11, 2025 examined 15,000 long-tail prompts and reported that, on average, 12% of links cited by ChatGPT, Gemini, and Copilot appeared in Google's Top 10 for the same prompt. This report is an independent niche-specific derivative using US-English questions, Google organic Top 20, explicit ChatGPT and Gemini citations, and the vertical scope named above. The study populations, surfaces, rank cutoffs, and aggregation rules differ, so the percentages are not directly comparable.

Exact URL coverage

The chart places the two primary conditional task-macro estimates on a shared scale, but each surface uses its own eligible task-cell set. The bars must not be subtracted as a paired-platform effect. It does not treat missing cells as zero. Primary estimates include only eligible paired Google Top 20 captures; exact eligible denominators are shown for every estimate. Exact 95% task-clustered intervals, pooled secondary estimates, and the available-pool sensitivity appear in the evidence table.

Exact URL coverage by vertical and AI surface

Surface-specific eligible sets; 95% task-clustered intervals and denominators are in the evidence table.

  1. Dentistry

    ChatGPT7.1%
    Gemini53.5%

  2. Fertility

    ChatGPT23.6%
    Gemini62.3%

  3. Dermatology

    ChatGPT19.5%
    Gemini53.3%

  4. Plastic Surgery

    ChatGPT15.7%
    Gemini49.2%

  5. Aesthetic Medicine & Medspa

    ChatGPT11.9%
    Gemini45.9%

  6. Ophthalmology

    ChatGPT14.4%
    Gemini59.3%

  7. Orthopedics

    ChatGPT12.9%
    Gemini56.1%

  8. Behavioral Health

    ChatGPT5.1%
    Gemini44.9%

  9. Addiction Treatment

    ChatGPT11.2%
    Gemini52.4%

  10. Bariatrics

    ChatGPT10.4%
    Gemini51.2%

  11. Urgent Care

    ChatGPT9.1%
    Gemini52.4%

  12. Medical Imaging

    ChatGPT14.1%
    Gemini65.9%

Verified Rotgar Research artifact · DataForSEO surfaces ·

Registrable-domain coverage

This view repeats the surface-specific display after URLs are collapsed to registrable domains. Eligible support can differ between ChatGPT and Gemini, so the side-by-side bars are not a paired-platform contrast. It describes source-domain coincidence only; it is not a source-authority or quality score.

Registrable-domain coverage by vertical and AI surface

Surface-specific eligible sets; 95% task-clustered intervals and denominators are in the evidence table.

  1. Dentistry

    ChatGPT19.3%
    Gemini56.7%

  2. Fertility

    ChatGPT41.8%
    Gemini84.5%

  3. Dermatology

    ChatGPT55.4%
    Gemini65.7%

  4. Plastic Surgery

    ChatGPT44.2%
    Gemini66.9%

  5. Aesthetic Medicine & Medspa

    ChatGPT31.1%
    Gemini52.5%

  6. Ophthalmology

    ChatGPT39.6%
    Gemini76.0%

  7. Orthopedics

    ChatGPT30.9%
    Gemini75.0%

  8. Behavioral Health

    ChatGPT40.4%
    Gemini55.3%

  9. Addiction Treatment

    ChatGPT37.5%
    Gemini66.7%

  10. Bariatrics

    ChatGPT48.7%
    Gemini68.5%

  11. Urgent Care

    ChatGPT33.9%
    Gemini67.9%

  12. Medical Imaging

    ChatGPT50.6%
    Gemini84.3%

Verified Rotgar Research artifact · DataForSEO surfaces ·

Citation-set similarity across AI surfaces

The mean task-level registrable-domain Jaccard was Dentistry 4.8% (28/36 eligible tasks); Fertility 8.2% (27/36 eligible tasks); Dermatology 11.0% (30/36 eligible tasks); Plastic Surgery 8.3% (29/36 eligible tasks); Aesthetic Medicine & Medspa 3.1% (27/36 eligible tasks); Ophthalmology 9.7% (26/36 eligible tasks); Orthopedics 9.7% (27/36 eligible tasks); Behavioral Health 5.2% (29/36 eligible tasks); Addiction Treatment 4.5% (26/36 eligible tasks); Bariatrics 16.3% (28/36 eligible tasks); Urgent Care 7.9% (27/36 eligible tasks); Medical Imaging 9.3% (32/36 eligible tasks). The denominator is each task's union of ChatGPT and Gemini citation domains; tasks without an eligible pair are NA.

ChatGPT–Gemini citation-domain Jaccard by vertical

Mean task-level intersection divided by union among eligible paired AI citation sets.

  1. Dentistry4.8%
    28 of 36 tasks eligible
  2. Fertility8.2%
    27 of 36 tasks eligible
  3. Dermatology11.0%
    30 of 36 tasks eligible
  4. Plastic Surgery8.3%
    29 of 36 tasks eligible
  5. Aesthetic Medicine & Medspa3.1%
    27 of 36 tasks eligible
  6. Ophthalmology9.7%
    26 of 36 tasks eligible
  7. Orthopedics9.7%
    27 of 36 tasks eligible
  8. Behavioral Health5.2%
    29 of 36 tasks eligible
  9. Addiction Treatment4.5%
    26 of 36 tasks eligible
  10. Bariatrics16.3%
    28 of 36 tasks eligible
  11. Urgent Care7.9%
    27 of 36 tasks eligible
  12. Medical Imaging9.3%
    32 of 36 tasks eligible

Verified Rotgar Research artifact · DataForSEO surfaces ·

Common-support platform comparison

A direct descriptive surface comparison must use the same eligible tasks. Across the included verticals, the common-support set contains 322 tasks for URL coverage and 322 tasks for domain coverage. The table shows each surface's macro mean and Gemini minus ChatGPT in percentage points; no causal or paired-bootstrap claim is attached to this derived display.

Common-support ChatGPT and Gemini comparison

Both surfaces are averaged over the same eligible tasks; differences are descriptive point estimates.

Verified Rotgar Research artifact · DataForSEO surfaces ·
ScopeURL common nChatGPT URLGemini URLGemini − ChatGPT URLDomain common nChatGPT domainGemini domainGemini − ChatGPT domain
Dentistry187.0%53.5%+46.4 pp1818.3%56.7%+38.4 pp
Fertility2327.8%62.3%+34.5 pp2347.5%84.5%+36.9 pp
Dermatology3018.5%53.3%+34.8 pp3054.0%65.7%+11.7 pp
Plastic Surgery2915.9%49.2%+33.3 pp2945.5%66.9%+21.4 pp
Aesthetic Medicine & Medspa2711.9%45.9%+34.0 pp2729.1%52.5%+23.3 pp
Ophthalmology2616.0%59.3%+43.3 pp2638.2%76.0%+37.8 pp
Orthopedics2714.1%56.1%+42.1 pp2730.7%75.0%+44.3 pp
Behavioral Health295.1%44.9%+39.8 pp2936.4%55.3%+18.9 pp
Addiction Treatment2612.6%52.4%+39.8 pp2632.9%66.7%+33.7 pp
Bariatrics289.4%51.2%+41.8 pp2844.3%68.5%+24.2 pp
Urgent Care2710.9%52.4%+41.5 pp2737.6%67.9%+30.3 pp
Medical Imaging3213.9%65.9%+52.0 pp3252.2%84.3%+32.1 pp
Medical report scope32213.6%53.9%+40.3 pp32239.8%68.6%+28.8 pp

Evidence table

Primary macro estimates give each eligible task cell equal weight. Pooled estimates instead weight cells by cited-source count and are secondary. Available-pool sensitivity uses fewer than 20 Google URLs where necessary and must not be read as the strict primary estimate. Primary estimates include only eligible paired Google Top 20 captures; exact eligible denominators are shown for every estimate.

Coverage estimates and denominators

Primary task-macro, secondary pooled, and available-pool sensitivity estimates are shown separately. Primary estimates include only eligible paired Google Top 20 captures; exact eligible denominators are shown for every estimate.

Verified Rotgar Research artifact · DataForSEO surfaces ·
VerticalAI surfaceURL macro [95% CI]URL pooled (secondary)URL available-pool sensitivityDomain macro [95% CI]Domain pooled (secondary)Domain available-pool sensitivityPrimary eligible cellsAvailable-pool eligible cells
DentistryChatGPT7.1% [2.1%, 13.7%]8.3%7.0%19.3% [9.7%, 30.6%]19.8%18.1%2327
DentistryGemini53.5% [36.3%, 70.3%]46.6%47.9%56.7% [41.4%, 71.6%]50.7%50.6%1822
FertilityChatGPT23.6% [14.6%, 33.5%]23.6%22.0%41.8% [30.2%, 54.0%]43.0%39.1%3034
FertilityGemini62.3% [50.0%, 74.3%]58.1%60.9%84.5% [75.9%, 92.5%]80.2%82.8%2326
DermatologyChatGPT19.5% [13.8%, 25.4%]17.8%19.5%55.4% [44.5%, 66.2%]50.4%55.4%3636
DermatologyGemini53.3% [41.6%, 64.5%]54.5%53.3%65.7% [54.0%, 76.5%]66.7%65.7%3030
Plastic SurgeryChatGPT15.7% [10.8%, 20.9%]13.5%15.7%44.2% [34.0%, 54.7%]41.4%44.2%3636
Plastic SurgeryGemini49.2% [40.8%, 58.3%]46.9%49.2%66.9% [58.7%, 74.9%]65.3%66.9%2929
Aesthetic Medicine & MedspaChatGPT11.9% [6.2%, 18.5%]9.8%11.9%31.1% [20.7%, 42.4%]25.2%31.1%3636
Aesthetic Medicine & MedspaGemini45.9% [34.6%, 57.6%]40.4%45.9%52.5% [40.5%, 64.8%]47.1%52.5%2727
OphthalmologyChatGPT14.4% [9.2%, 20.2%]14.8%14.4%39.6% [29.5%, 50.0%]43.9%39.6%3636
OphthalmologyGemini59.3% [47.9%, 70.1%]60.2%59.3%76.0% [68.6%, 83.3%]73.3%76.0%2626
OrthopedicsChatGPT12.9% [8.4%, 17.9%]14.0%12.9%30.9% [22.3%, 40.0%]32.2%30.9%3636
OrthopedicsGemini56.1% [45.8%, 66.6%]48.2%56.1%75.0% [64.0%, 85.5%]66.3%75.0%2727
Behavioral HealthChatGPT5.1% [1.5%, 9.5%]4.0%5.1%40.4% [31.5%, 49.6%]35.9%40.4%3636
Behavioral HealthGemini44.9% [34.3%, 55.9%]41.3%44.9%55.3% [46.0%, 64.6%]52.5%55.3%2929
Addiction TreatmentChatGPT11.2% [6.6%, 16.3%]10.2%11.2%37.5% [27.8%, 47.7%]34.4%37.5%3636
Addiction TreatmentGemini52.4% [42.2%, 63.1%]51.6%52.4%66.7% [55.9%, 77.5%]64.4%66.7%2626
BariatricsChatGPT10.4% [6.8%, 14.2%]10.7%10.4%48.7% [38.0%, 59.6%]48.9%48.7%3636
BariatricsGemini51.2% [38.5%, 64.0%]43.8%51.2%68.5% [56.2%, 79.8%]64.6%68.5%2828
Urgent CareChatGPT9.1% [4.8%, 13.8%]9.4%9.1%33.9% [24.6%, 43.3%]37.3%33.9%3636
Urgent CareGemini52.4% [41.2%, 63.3%]52.2%52.4%67.9% [56.4%, 78.6%]70.8%67.9%2727
Medical ImagingChatGPT14.1% [9.7%, 18.8%]15.1%14.1%50.6% [40.0%, 61.1%]50.0%50.6%3636
Medical ImagingGemini65.9% [56.3%, 75.4%]61.3%65.9%84.3% [77.4%, 90.7%]81.4%84.3%3232

Frequently observed citation domains

The following audited tables rank registrable domains only by observed frequency in this report's task set. Counts and distinct-task support are descriptive; they are not authority, quality, trust, or optimization scores. Example source URLs are retained in the tables for auditability and are not used to make narrative claims.

Most frequently observed AI-cited registrable domains

Top 10 per AI surface by distinct task count; frequency is not authority or quality.

Verified Rotgar Research artifact · DataForSEO surfaces ·
AI surfaceFrequency rankRegistrable domainDistinct tasksTask-level cited URL appearancesDistinct normalized URLsExample cited URL
ChatGPT1nih.gov4612784alcoholtreatment.niaaa.nih.gov
ChatGPT2plasticsurgery.org388457find.plasticsurgery.org/city/beverly-hills
ChatGPT3fda.gov387042www.accessdata.fda.gov/cdrh_docs/pdf6/P060004S006D.pdf
ChatGPT4reddit.com354039www.reddit.com/r/AskChicago/comments/1coxmlw/invisalign_in_chicago
ChatGPT5aad.org337338www.aad.org/member/clinical-quality/guidelines/atopic-dermatitis
ChatGPT6uclahealth.org324735www.uclahealth.org/departments/radiology/about-us/our-locations
ChatGPT7realself.com303623www.realself.com/dr/andrew-jacono-new-york-ny
ChatGPT8samhsa.gov265124www.samhsa.gov/blog/substance-use-disorders-treatment-options
ChatGPT9uchicagomedicine.org243124www.uchicagomedicine.org/cancer/types-treatments/breast-cancer/screening-diagnosis
ChatGPT10cdc.gov234130archive.cdc.gov/www_cdc_gov/coronavirus/2019-ncov/hcp/clinical-care/clinical-considerations-presentation.html
Gemini1mdsave.com192019www.mdsave.com/procedures/2d-mammogram-screening/d786fcc5/new-york
Gemini2newchoicehealth.com162020www.newchoicehealth.com/hip-replacement-surgery/cost
Gemini3mountsinai.org151513www.mountsinai.org/about/insurance/price-transparency
Gemini4mayoclinic.org131715newsnetwork.mayoclinic.org/discussion/mayo-clinic-qa-its-a-new-era-for-knee-replacements-and-other-joint-surgeries
Gemini5plasticsurgery.org111413www.plasticsurgery.org/cosmetic-procedures/dermal-fillers/cost
Gemini6uclahealth.org111313www.uclahealth.org/departments/eye
Gemini7nyulangone.org111211nyulangone.org/care-services/hip-center
Gemini8nm.org10119www.nm.org/conditions-and-care-areas/behavioral-health
Gemini9goodrx.com10108www.goodrx.com/conditions/acne/cost-of-acne-complications
Gemini10radiologyassist.com10109radiologyassist.com/StagingAvada/facility-locations-rates/locations-by-city/ct-scan/los-angeles-ca-ct-scan

Most frequently observed matched registrable domains

Top 10 per AI surface among domain matches; frequency is not authority or quality.

Verified Rotgar Research artifact · DataForSEO surfaces ·
AI surfaceFrequency rankRegistrable domainDistinct tasksMatched cited URL appearancesDistinct AI URLsExample AI-cited URLExample paired Google URL
ChatGPT1nih.gov4011881alcoholtreatment.niaaa.nih.govalcoholtreatment.niaaa.nih.gov/how-to-find-alcohol-treatment/how-to-search-what-to-ask/step-2-ask-10-recommended-questions
ChatGPT2plasticsurgery.org296747find.plasticsurgery.org/city/chicago/for-medical-professionalsfind.plasticsurgery.org/city/chicago
ChatGPT3uclahealth.org243629www.uclahealth.org/departments/radiology/about-us/our-locationswww.uclahealth.org/cancer/cancer-services/skin-cancer
ChatGPT4reddit.com182323www.reddit.com/r/AskChicago/comments/1q7eunh/fertility_clinic_recommendationswww.reddit.com/r/30PlusSkinCare/comments/16uvfyf/looking_for_reasonablypriced_dermatologists_and
ChatGPT5psychologytoday.com163434www.psychologytoday.com/us/psychiatrists/ahmad-a-mohammad-brooklyn-ny/1426505www.psychologytoday.com/us/basics/therapy/cost-and-insurance-coverage
ChatGPT6nyulangone.org162119nyulangone.org/care-services/ct-scansnyulangone.org/care-services/ct-scans
ChatGPT7uchicagomedicine.org162116www.uchicagomedicine.org/cancer/types-treatments/breast-cancer/screening-diagnosiswww.uchicagomedicine.org/conditions-services/dermatology/treatments-and-services/cosmetic-dermatology
ChatGPT8aad.org153624www.aad.org/member/practice/telederm/standardswww.aad.org/member/clinical-quality/guidelines/acne
ChatGPT9mountsinai.org152221profiles.mountsinai.org/edward-kwakwww.mountsinai.org/care/dermatology/services/acne
ChatGPT10nm.org141916encyclopedia.nm.org/Library/HealthSheets/3%2CS%2C84321www.nm.org/conditions-and-care-areas/behavioral-health/behavioral-health-services-western-suburbs/substance-abuse-and-addiction
Gemini1mdsave.com171818www.mdsave.com/procedures/2d-mammogram-screening/d786fcc5/new-yorkwww.mdsave.com/procedures/2d-mammogram-screening/d786fcc5/new-york
Gemini2newchoicehealth.com151919www.newchoicehealth.com/hip-replacement-surgery/costwww.newchoicehealth.com/places/california/los-angeles/arthroscopic-shoulder-surgery
Gemini3mountsinai.org121210www.mountsinai.org/care/dermatology/services/acnewww.mountsinai.org/care/dermatology/services/acne
Gemini4plasticsurgery.org111413www.plasticsurgery.org/cosmetic-procedures/dermal-fillers/costwww.plasticsurgery.org/cosmetic-procedures/breast-augmentation/recovery
Gemini5radiologyassist.com10109radiologyassist.com/StagingAvada/facility-locations-rates/locations-by-city/ct-scan/los-angeles-ca-ct-scanradiologyassist.com/StagingAvada/facility-locations-rates/locations-by-city/ct-scan/los-angeles-ca-ct-scan
Gemini6uclahealth.org91111www.uclahealth.org/departments/eyewww.uclahealth.org/departments/radiology/education/breast-imaging-teaching-resources/screening-mammogram/high-risk-patient-population
Gemini7nm.org9108www.nm.org/conditions-and-care-areas/cancer-care/dermatologic-cancers/skin-cancer/specialists-and-care-centerswww.nm.org/conditions-and-care-areas/cancer-care/dermatologic-cancers
Gemini8cedars-sinai.org787www.cedars-sinai.org/programs/dermatology.htmlwww.cedars-sinai.org/programs/dermatology.html
Gemini9nyulangone.org787nyulangone.org/care-services/hip-centernyulangone.org/care-services/hip-center
Gemini10goodrx.com776www.goodrx.com/conditions/breast-cancer/how-much-mammogram-costwww.goodrx.com/conditions/breast-cancer/how-much-mammogram-cost

Methodology

20-niche exploratory source-overlap panel uses a frozen 720-question manifest; this report contains 432 questions across 12 named niches, with 36 questions per niche. Each question pairs Google, ChatGPT, and Gemini captures. Google eligibility uses organic results sorted by group rank, normalized-URL deduplication, and the first 20 unique eligible URLs. AI inputs are explicitly cited sources only.

Primary estimates include only eligible paired Google Top 20 captures; exact eligible denominators are shown for every estimate.

The primary URL and domain metrics divide the within-task matched AI source count by that AI cell's unique cited-source count, then take an unweighted macro mean across eligible cells. A citation-bearing eligible cell with no match is zero. A no-citation cell is NA and is counted separately. Registrable domains use the analyzer's pinned Public Suffix List logic. The pooled estimate is secondary; the available-pool estimate is a labeled sensitivity for present Google pools below the strict Top 20. ChatGPT–Gemini domain Jaccard is computed within task before the vertical macro mean. No source-class taxonomy is inferred. Primary coverage intervals use 10,000 percentile bootstrap replicates with seed 20260807, resampling tasks within vertical and retaining each sampled task's available surface cells.

All 720 manifest rows retain reviewer_status=unreviewed. No licensed medical or legal domain reviewer evaluated the question set or answers. Therefore this study supports source-overlap findings only, not clinical/legal accuracy, safety, or completeness.

The dataset was collected through DataForSEO mixed live and Standard queue endpoints, not through repeated logged-in consumer UI sessions. Endpoint observations were chatgpt: /v3/ai_optimization/chat_gpt/llm_scraper/live/advanced, /v3/ai_optimization/chat_gpt/llm_scraper/task_get/advanced; gemini: /v3/ai_optimization/gemini/llm_scraper/live/advanced, /v3/ai_optimization/gemini/llm_scraper/task_get/advanced; google: /v3/serp/google/organic/live/advanced, /v3/serp/google/organic/task_get/advanced. Returned collection-time model labels were chatgpt: gpt-5-5, gpt-5-6; gemini: 3.5 Flash-Lite; google: not_exposed. In this report, ChatGPT and Gemini mean those mediated surfaces and returned labels; endpoint behavior may differ from consumer UI.

The 16 added niches were selected after aggregate results for four original niches had been inspected. Original and extension observations were collected in different windows and through live versus Standard queue endpoints; vertical is therefore confounded with timing and retrieval mode. Cross-niche results are descriptive.

Scope and reproducibility

Dentistry: topic anchors — clear aligners, dental implants, and emergency dental care; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Fertility: topic anchors — IUI, IVF, and egg freezing; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Dermatology: topic anchors — acne treatment, eczema treatment, and skin cancer screening; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Plastic Surgery: topic anchors — breast augmentation, facelift, and rhinoplasty; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Aesthetic Medicine & Medspa: topic anchors — dermal fillers, laser skin resurfacing, and neuromodulator injections; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Ophthalmology: topic anchors — LASIK eye surgery, cataract surgery, and glaucoma treatment; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Orthopedics: topic anchors — hip replacement, knee replacement, and rotator cuff treatment; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Behavioral Health: topic anchors — anxiety therapy, depression treatment, and psychiatric evaluation; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Addiction Treatment: topic anchors — alcohol use disorder treatment, opioid use disorder treatment, and outpatient addiction treatment; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Bariatrics: topic anchors — gastric bypass surgery, gastric sleeve surgery, and medical weight management; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Urgent Care: topic anchors — minor injury treatment, on-site X-ray imaging, and respiratory infection treatment; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

Medical Imaging: topic anchors — CT scan, MRI scan, and screening mammogram; intent families — Authoritative-source seeking, Comparison/choice, Eligibility/requirements, Local cost, Local provider discovery, and Process/timeline

The full exact wording, geography, topic anchor, and intent family for all 720 questions remain in FULL-QUERY-MANIFEST.csv. The frozen estimands and normalization rules are in PROTOCOL-EXTENSION.md; collection and analysis departures are recorded in DEVIATIONS.csv. The artifact source metadata includes the exact file identities and SHA-256 hashes used for this build.

What this means for medical organizations

Medical organizations can use this benchmark to see how source overlap varies across sampled patient questions and medical niches. It can guide separate measurement of Google visibility and AI citation visibility, but it does not predict rankings, citations, patient demand, clinical accuracy, or care quality.

Further questions

  • Which page and domain overlaps recur in a later frozen observation window?
  • Do observed patterns remain after stratifying by intent family and geography without creating underpowered slices?
  • Which cited pages warrant a separate reviewed qualitative taxonomy, and what annotation protocol would make that classification reproducible?
  • How stable are the observed overlaps after later platform and model changes?

Limitations

All 720 manifest rows retain reviewer_status=unreviewed. No licensed medical or legal domain reviewer evaluated the question set or answers. Therefore this study supports source-overlap findings only, not clinical/legal accuracy, safety, or completeness.

The dataset was collected through DataForSEO mixed live and Standard queue endpoints, not through repeated logged-in consumer UI sessions. Endpoint observations were chatgpt: /v3/ai_optimization/chat_gpt/llm_scraper/live/advanced, /v3/ai_optimization/chat_gpt/llm_scraper/task_get/advanced; gemini: /v3/ai_optimization/gemini/llm_scraper/live/advanced, /v3/ai_optimization/gemini/llm_scraper/task_get/advanced; google: /v3/serp/google/organic/live/advanced, /v3/serp/google/organic/task_get/advanced. Returned collection-time model labels were chatgpt: gpt-5-5, gpt-5-6; gemini: 3.5 Flash-Lite; google: not_exposed. In this report, ChatGPT and Gemini mean those mediated surfaces and returned labels; endpoint behavior may differ from consumer UI.

This is a 20-niche exploratory source-overlap panel snapshot, not a causal study or a performance forecast. Primary estimates include only eligible paired Google Top 20 captures; exact eligible denominators are shown for every estimate. Available-pool sensitivity is reported separately from the strict primary estimates. No-citation AI cells remain NA rather than zero.

The study observes explicitly exposed citations, not every source used internally by a model. URL or domain coincidence does not establish answer accuracy, source quality, endorsement, user attention, rankings, traffic, leads, matters, or patient outcomes. ChatGPT and Gemini surface-specific estimates can use different eligible tasks; their raw difference is not presented as a paired effect. The 95% task-clustered percentile intervals describe sampling variability under the stated bootstrap, not causal uncertainty. Platform models and returned sources can change after capture. Rank-position distributions and source-class claims are outside this report.

The 16 added niches were selected after aggregate results for four original niches had been inspected. Original and extension observations were collected in different windows and through live versus Standard queue endpoints; vertical is therefore confounded with timing and retrieval mode. Cross-niche results are descriptive.

Download and cite

Use the published evidence without losing its context

The public files preserve labels, denominators and scope notes from this version of the study. Downloads are available without an email gate.

XLSX

Analysis workbook

Formatted workbook with the study summary, niche results, task-level metrics, question manifest and data dictionary.

Format
application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Size
87.8 KB
sha256:43e2981c0164395a1b91f110086eabe1661c11d40ffe63a71a76440b41484d9f
CSV

Summary results (CSV)

Machine-readable study-level and niche-level overlap estimates with their eligible denominators.

Format
text/csv
Size
3.5 KB
sha256:ba51e52a7e7777f2a06d2261b0a19c4b3d8664355d62df43f3daa2f020ecbcb2
JSON

Structured study data (JSON)

The published summary, metadata and nested result records in a structured format.

Format
application/json
Size
16.6 KB
sha256:cd5a9018a0efea7c5284eab2fe08e9b1fed25b8e600684d56d2fea8996d825d4
CSV

Question and prompt manifest

The full US-English question and paired AI-prompt manifest used for this study.

Format
text/csv
Size
225.6 KB
sha256:922e8f3c8676492a240344a5762c72ad7f6eb285650e785490a716dd0559cf02
CSV

Data dictionary

Field definitions, units, denominator rules and interpretation notes for the published tables.

Format
text/csv
Size
6.0 KB
sha256:ea708862db53234e1b15769610b2e95ac045bc8b14b0c6a8f58a0e26be70c4bf
BibTeX

BibTeX citation

A ready-to-import citation record for reference managers and research documents.

Format
text/plain
Size
465 B
sha256:bcd0830fad3d5bc56ec53179e67dc041be3ad10c761c26ef5aeb4ca1e23637a5
CFF

Citation File Format

Machine-readable citation metadata in Citation File Format 1.2.

Format
text/plain
Size
650 B
sha256:ae06ff8d9907b39ce273d5063b9cdcb7961933924678b99c687e031ec80727b6
SVG

Common-support comparison figure

Reusable vector figure comparing ChatGPT and Gemini on the same eligible tasks.

Format
image/svg+xml
Size
4.6 KB
sha256:0ee545ebca0d770026148bf8c3c1fed214c7379f5fea9f71d976ae6c71a4a995

Cite this study

Yudin, E. (2026). Google and AI Source Overlap Across 12 Medical Niches (Version 1.0) [Data set]. Rotgar Research. https://doi.org/10.5281/zenodo.21850734

Artifact provenance

Verified inputs remain traceable

The published page is generated from the verified report artifact. The build stops if its receipt, SHA-256, niche set or denominators no longer match the approved evidence package.

Artifact SHA-25604ca9c37b1d8f70e171c6bd5d8cf962d45039b344e4adf313b56ebeb51f34548

Review evidence identities
  • Expanded ICP panel paired task metricssha256:9e11fbc71161f3e3b9849f45273c6d83ba528a78c73753b03ec81338258f9933
  • Expanded ICP panel aggregate metricssha256:26024fd79907e43a5a3cfa6dd63b665d846034395f5b63fa7f538ca4fcc3700e
  • Expanded ICP panel task-level AI domain Jaccardsha256:3cfd40580e3659eeb7f332f5598abce611e1efd1ef81ca4a572b0cc942001c37
  • Expanded ICP panel data-quality checkssha256:34d941d5cd2ab029c64936f52d46099ea4667e4515ac9ac203e9ca237032cf79
  • Expanded ICP panel deduplicated sourcessha256:09e2764a31ed9a5b2359d3ecb1cc6d6f0d7c4f516225cd9e61b17386e6a1f4fc
  • Expanded ICP panel paired Google matchessha256:c76097b6cea95f956446e017ced1c8d9825c9e3828b9b001aa214dd86b1783fa
  • Expanded ICP panel analysis summarysha256:8081c495575736e82dc1630dd240282d40a51e712e12082a1dee406772db55ef
  • AI source-overlap protocolsha256:79134959f213e7ad67bd430f679b680bebf741fb27dd3904745a62dcf9dfc421
  • Frozen 720-question manifestsha256:bf9692248628180555a7d95d3b5b85b037ebcaf52480c2a88ece46341f920bc0
  • Study deviations registersha256:6439adae3132037cf0c4419298e32612fd126dcead641bbe4b69c891e89d0744
  • Expanded ICP panel collection summarysha256:489a4f089791a63fcb7e6ef6c8a971de30b31d1cc7eec755cf1f0842fdd2a495
  • Expanded ICP panel endpoint and model run ledgersha256:5453efa3591ad002a5f0821e549bb130e40dcf3268bebb6cba6cce63a1c3fead
  • Deterministic Expanded ICP panel report derivationsha256-input-bundle:23bb060606221774ce71e9e8c0fbb059a4b9c885538d6d79999435948c1f5658
  • Executed Expanded ICP panel report materialization queriessha256:87580b34057e48a3cfcb5e7b1f099c43b690f833f8a26b0a9217fd366930c813
  • Ahrefs AI search overlap studyahrefs-ai-search-overlap-2025-08-11

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