Hand holding a Social Media 3d Sphere

Social Media Index (SMi)

Academics have created indices to compare both scholars (h-index) and journals (Impact Factor) within a given field. The websites that contribute to the creation of Free Open Access Medical Education (FOAM) do not have a comparable parameter. This makes assessing the impact of each website challenging for both content producers and their supervisors. Additionally, learners may find it difficult to distinguish between reputable and unproven websites.

The Social Media Index (SMi) was developed to address these problems. It is a comparative index derived from three easily obtainable indicators including:

  1. Alexa Rank (of the website)
  2. Twitter Followers (of the most prominent editor)
  3. Facebook Likes (of the website’s page)

For each website, these 3 indicators are normalized and added together to give a score ranging from 0 to 10. The details of the derivation and validation of the SMi are outlined in the Western Journal of Emergency Medicine1 while a study investigating the SMi’s correlation with quality has recently been published in Annals of Emergency Medicine.2

Social Media Index

Social Media Index: December 2018 Update

WebsiteJun 15.Nov 15.June 16.Nov 16.Apr 17.Dec 17.Jun 18.Dec 18.
EMCrit Blog22222222
Dr Smiths ECG Blog66656654
Rebel EM99877545
Emergency Medicine Cases1310765776
EM Docs23201298887
EMS 12 lead45444469
Intensive Care Network16129811131210
First 10 EM4335411922191611
Dont Forget the Bubbles721514213151912
The Skeptics guide to EM2023181717161814
St Emlyns Blog515101010111315
Emergency Medicine updates2218191818142016
Emergency Ultrasound Podcast1514141219182117
EM Basic2522171515171418
Critical Care Practitioner4743233131262321
Taming the SRU4129282328353022
The Poison Review3213151616242823
Ultrasound of the Week1826252227231724
EM Lit of note2617161323291525
Resus ME1928202120252726
Flight Bridge ED17NR394842393227
Sinai EM US3046425245464529
PEM Blog2144373639373630
Pediatric EM Morsels3749494646274032
Pharmacy Joe42NR456238423933
ED Exam3347343236384134
The EM Res PodcastNR54575544404735
Everyday Medicine3433323541434336
Western Sono6662754153504437
The EDE Blog6867659772685839
EM Curious7439405343413840
Broome Docs9059625455604241
Clinical Monster49NR1018569576042
Rogue Medic3648464051525243
Sinai EM MediaNR57737864565144
Intensive Blog39NR555759593545
Emottawa blogNRNR150137132967947
EMJ ClubNR53613757616649
EM in 550145687574724650

Social Media Index: Latest numbers

WebsiteAlexaTwitterFacebookSocial Media Index
EMCrit Blog15746445030284228.16
Dr Smiths ECG Blog26692814478541567.53
Rebel EM24215017391126367.35
Emergency Medicine Cases2688407299220497.17
EM Docs256521675749226.87
EMS 12 lead1052638221451079896.64
Intensive Care Network8103951318673226.14
First 10 EM433732515916296.1
Dont Forget the Bubbles659644485044185.96
The Skeptics guide to EM11165461136353535.79
St Emlyns Blog11644191834436735.79
Emergency Medicine updates12059961085821515.53
Emergency Ultrasound Podcast11968451430415225.53
EM Basic13621621156618315.42
Critical Care Practitioner1030816487511965.33
Taming the SRU1013385393511285.28
The Poison Review1476871696113505.18
Ultrasound of the Week1503483644012835.14
EM Lit of note22090991065822515.11
Resus ME2443057165686964.9
Flight Bridge ED137705626767884.89
Sinai EM US123777217621284.48
PEM Blog192377414854904.42
Pediatric EM Morsels585769401304.2
Pharmacy Joe815553841504.11
ED Exam9794867315712433.79
The EM Res Podcast986266433226553.66
Everyday Medicine19995667157474273.64
Western Sono487240319521553.64
The EDE Blog26531411111343.57
EM Curious600111328391313.56
Broome Docs1667497762603.56
Clinical Monster1087425168103.52
Rogue Medic2864432489543.5
Sinai EM Media1243185174203.43
Intensive Blog1880920591903.42
Emottawa blog1306716457915353.29
EMJ Club1155285013063983.25
EM in 51671272188303.23


As this is still a beta version, we would appreciate your assistance in correcting any errors (Did we miss an Alexa Rank, Twitter Account, or Facebook page? Is our data inaccurate?). Feedback on the SMi can also be provided by commenting on this page or tweeting @Brent_Thoma.

Update: Removal of PageRank

Google deprecated the PageRank metric after our original publication1 in 2013. Because of this, PageRank will no longer be included in future versions of the SMi.

Fortunately, our data in the 2013 WestJEM paper suggests that the Alexa score has a high correlation to PageRank. Because of this, we have elected to double the weight of the Alexa score in the SMi calculation to replace PageRank’s contribution. We have also modified the calculation of the Alexa component of the SMi. This change fixes the lowest ranking websites to a value of 0, which increases the range of values. The effect of this change makes the score more consistent with the other components. The current formula has been shown to correlate with quality.2

The detailed formula is:

Social Media index



Thoma B, Sanders J, Lin M, Paterson Q, Steeg J, Chan T. The social media index: measuring the impact of emergency medicine and critical care websites. West J Emerg Med. 2015;16(2):242-249. [PubMed]
Thoma B, Chan T, Kapur P, et al. The Social Media Index as an Indicator of Quality for Emergency Medicine Blogs: A METRIQ Study. Ann Emerg Med. July 2018. [PubMed]