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

2020 Social Media Index (SMi) Rankings

The SMi ranking table demonstrates the annual rankings of each site since 2016.
Rebel EM97554
EM Docs209875
Emergency Medicine Cases106766
First 10 EM351919117
Dr Smiths ECG Blog65649
EMS 12 lead544910
The Skeptics guide to EM2317161411
St Emlyns Blog1510111513
Emergency Ultrasound Podcast1412181714
Dont Forget the Bubbles2142151215
Flight Bridge EDNR48392716
Intensive Care Network128131017
Emergency Medicine updates1818141618
Ultrasound of the Week2622232419
EM Lit of note1713292521
EM Basic2215171822
Resus ME2821252623
Taming the SRU2923352224
The Poison Review1316242327
Critical Care Practitioner4331262130
EM Over EasyNRNR766231
PEM Blog4436373032
PedEM Morsels4946273234
Pharmacy JoeNR62423336
The EM Res Podcast5455403537
EMJ Club5337614938
Emottawa blogNR137964739
60 Second EM7770495240
EM Curious3953414041
Western Sono6241503742
County EMNR85574244
Broome Docs5954604145
Rolobot Rambles7865736146
Rogue Medic4840524349
Intensive BlogNR57594550
Thinking Critical Care110130978352
Rural Docs9396988753
The Short Coat86102878158
Adventures in Emergency Medicine1021131089359
KI Docs6156716561
EM in 514575725062
Emergency Medicine Ireland5577788263
Paediatric EM1281361219964
Emergency Medicine PharmD15286806665
EM IM Doc66681029066
Trauma Professionals blog6061636768
EM Sim CasesNR106867369
Resus Review8260846870
Asystole: The Most Stable Rhythm12111412411171
Rollcage Medic11512511610672
Sask Sonic1261381208073
The Sharp EndNR10811511474
Maryland CC Project127141705475
Auckland HEMS11811711810576
Hennepin Ultrasound7390669877
ECG of the Week12012312910378
Emergence Phenomena8066857779
Emergency Room Nurse11913313611880

2020 Social Media Index (SMi) Values

The SMi values table demonstrates the Alexa, Facebook, and Twitter values collected for each site for the 2020 SMi.
WebsiteAlexaTwitterFacebookSocial Media Index
Rebel EM37135920400156006.31
EM Docs256521848165806.21
Emergency Medicine Cases4712749864259236.08
First 10 EM299065794925445.87
Dr Smiths ECG Blog125126220600601475.79
EMS 12 lead3036838233001082995.43
The Skeptics guide to EM13356321490071465.21
St Emlyns Blog14930582140042035.11
Emergency Ultrasound Podcast9618611510016195.1
Dont Forget the Bubbles1256408685178255.09
Flight Bridge ED52578134259395.05
Intensive Care Network35684831400081514.66
Emergency Medicine updates21049331240023834.66
Ultrasound of the Week1507118772513314.62
EM Lit of note36753211160024784.35
EM Basic39236721340019344.29
Resus ME3177112182007414.27
Taming the SRU2649027448713464.18
The Poison Review4912543720713773.96
Critical Care Practitioner10172229582114563.57
EM Over Easy412596019034763.51
PEM Blog497967918456293.47
PedEM Morsels813067437403.33
Pharmacy Joe1091788884203.3
The EM Res Podcast1017222932866983.28
EMJ Club667583713365173.21
Emottawa blog1017222973217143.12
60 Second EM521288815811503.01
EM Curious1017222929761422.91
Western Sono1017222922841602.88
County EM1527553192702.75
Broome Docs2763685831902.74
Rolobot Rambles34174121100002.69
Rogue Medic69871244610032.56
Intensive Blog3615171679002.55
Thinking Critical Care3895213323102.34
Rural Docs6687896938802.31
The Short Coat101722291030002.13
Adventures in Emergency Medicine5273328249202.12
KI Docs10172229938802.11
EM in 54984798196402.09
Emergency Medicine Ireland8876039652802.09
Paediatric EM4660043160602.08
Emergency Medicine PharmD6373133261702.04
EM IM Doc10172229570901.99
Trauma Professionals blog10172229345101.87
EM Sim Cases371713629601.81
Resus Review7517828125001.79
Asystole: The Most Stable Rhythm715486588801.73
Rollcage Medic10172229183401.73
Sask Sonic10172229136501.66
The Sharp End679253955101.65
Maryland CC Project1017222993801.58
Auckland HEMS1017222993301.57
Hennepin Ultrasound1017222990101.57
ECG of the Week893519857501.52
Emergence Phenomena1017222954101.45
Emergency Room Nurse38734754401.36

SMI Calculator


The detailed formula for the calculation of the SMi for an individual website is outlined below. Notably, each aspect must be related to the site on the index relative to the other sites highest/lowest Alexa, Twitter, and Facebook numbers:

Social Media index


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 tweeting @Brent_Thoma.


There have been numerous updates to the SMi over the years.

2013: Google deprecated the PageRank metric after our original publication1 and it was 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 the lowest value achieved by any indexed site. The effect of this change makes the score more consistent with the other components.

2018: The current formula was shown to correlate with quality.2

2019: Given the time demands of data collection, we transitioned to an annual data collection in December of each year that would be considered the subsequent year’s SMi for each site (e.g. data collected in December of 2019 make up the 2020 SMi).

2020: The inclusion criteria for each website has been clarified. Moving forward, sites already indexed will be retained for the subsequent year if they

  1. Focus on emergency medicine or critical care content
  2. Receive an Alexa score OR have posted content within the last calendar year
  3. Have either a Twitter page (editor- or site-specific) OR Facebook page (site-specific)

Sites will be included moving forward if they are nominated by anyone (tweet any sites meeting the criteria to @Brent_Thoma). To be included they will need to:

  1. Focus on emergency medicine or critical care content
  2. Receive an Alexa score
  3. Have either a Twitter page (editor- or site-specific) OR Facebook page (site-specific)


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]