theDataMap

Documenting all the places
personal data goes.

Others Can Learn Your Medical Details


For $50, we purchased the publicly available dataset from Washington State. It contained virtually all hospitalizations occurring in the state in the year, including patient demographics, diagnoses, procedures, attending physician, hospital, a summary of charges, and how the bill was paid. It did not contain patient names or addresses (only five-digit ZIPs, which are U.S. postal codes).

Could your family, friends, an employer, or bank find you in the data? These people would know facts about hospital visits belonging to you. As a proxy for the information they would know, we used a sample of newspaper stories that reported on public incidents, such as car accidents and fires. These short reports often included a patient’s name and residential information and explained why the person was hospitalized, such as a vehicle accident or assault.

A simple analysis uniquely and exactly matched medical records in the state database for 35 of the 81 sampled news stories found in 2011 (or 43 percent), thereby putting names to patient records.

As a result of this work on the HealthDataMap, Washington State changed its way of sharing these data to create three levels of access. Anyone can download tabular summaries. Anyone can pay $50 and complete a data-use agreement to receive a redacted version of the data. However, access to all the fields provided prior to this experiment are now limited to applicants who qualify through a review process.

Below is demonstration of the matchup of the state health information with a newspaper story. [source].


How Big is this Risk?


The Washington State data appears on HealthDataMap as
discharge data. This kind of personal health information is the biggest provider of health data documented on the HealthDataMap. Because these datasets follow state law, they are not covered by the Health Information Portability and Accountability Act (HIPPA), which is the U.S. federal legislation that protects patient information. Only 3 states share the information using standards as tough as those prescribed by HIPAA. Most states (30) share data in a manner that is not as tough as HIPAA prescribes. Below is a statewise comparison of the datasets available through U.S. states. [source].

StateHIPAA Equivalence for Demographic DataHIPAA Equivalence for for Admission and DischargeHIPAA Equivalence or Better for Both
Alabama
Alaska
ArizonaNoNoNo
ArkansasYesNoNo
CaliforniaYesNoNo
ColoradoNoNoNo
Connecticut
Delaware
District of Columbia
FloridaNoYesNo
Georgia
HawaiiNoNoNo
Idaho
IllinoisStricterNoNo
Indiana
IowaNoNoNo
Kansas
KentuckyNoNoNo
Louisiana
MaineStricterNoNo
MarylandYesNoNo
MassachusettsYesNoNo
Michigan
Minnesota
Mississippi
MissouriYesYesYes
Montana
Nebraska
NevadaStricterNoNo
New HampshireNoYesNo
New JerseyNoNoNo
New MexicoYesNoNo
New YorkNoNoNo
North CarolinaNoNoNo
North Dakota
Ohio
OklahomaNoNoNo
OregonYesYesYes
PennsylvaniaNoYesNo
Rhode IslandStricterNoNo
South CarolinaStricterNoNo
South DakotaNoNoNo
TennesseeNoNoNo
TexasNoNoNo
UtahNoNoNo
VermontNoYesNo
VirginiaNoNoNo
WashingtonNoNoNo
West VirginiaStricterYesYes
WisconsinNoNoNo
Wyoming


What is the HIPAA Standard?


The Safe Harbor provision of the HIPAA Privacy Rule prescribes a way to share medical data publicly. Dates may only include the year. HIPAA requires that ZIP codes contain only the first three digits if the population in those ZIP codes is greater than 20,000. ZIP codes for populations less than 20,000 report a null ZIP of 00000. No explicit identifiers such as name, Social Security numbers, or addresses can appear. Below are specific combinations of demographic fields available by each state.

StateGenderAddressAge
Alabama
Alaska
ArizonaYes5 digit zip codeIn Years
ArkansasYes3 digit zip codeIn Years
CaliforniaYes3 digit (or nothing if not unique) subject to maskingIn Years (subject to masking)
ColoradoYes3 digit zip codeBirth month and year
Connecticut
Delaware
District of Columbia
FloridaYes5 digit zip codeIn Years
Georgia
HawaiiYes5 digit zip codeAge Group (Birth Year in HCUP)
Idaho
IllinoisYes3 digit zip codeAge Group
Indiana
IowaYes5 digit zip codeIn years
Kansas
KentuckyYes5 digit zip codeIn years
Louisiana
MaineYesCountyIn Years
MarylandYes3 digit zip codeIn Years
MassachusettsYes3 digit zip codeIn Years
Michigan
Minnesota
Mississippi
MissouriYesFirst 3 digits if first 3 digits of ZIP has population >20,000Birth year
Montana
Nebraska
NevadaYesStateIn Years
New HampshireYes5 digit zip codeIn Years
New JerseyYes5 digit zip codeIn Years
New MexicoYes3 digit zip codeIn Years
New YorkYes5 digit zip codeBirth month and year
North CarolinaYes5 digit zip codeIn Years
North Dakota
Ohio
OklahomaYes5 digit zip codeAge Group
OregonYes3 digit zip codeIn Years
PennsylvaniaYes5 digit zip codeIn Years
Rhode IslandYesRemoved in 2007In Years
South CarolinaYesCountyAge Group
South DakotaYes5 digit zip codeIn Years
TennesseeYesCounty, 5 digit zip codeIn Years
TexasYes5 digit zip code (last two digits are blank if a ZIP code has fewer than 30 cases)Age Group (expanded for HIV/drug/alcohol)
UtahYes5 digit zip codeAge Group
VermontYes3 digit zip code (categories; 5-digit if pop>10k)Age Group
VirginiaYes5 digit zip codeIn Years
WashingtonYes5 digit zip codeIn months
West VirginiaYesStateIn years
WisconsinYes5 digit zip codeIn years
Wyoming


Below are specific combinations of other fields available by each state that are not necessarily compliant with HIPAA.

StateAdmission DateDischarge DateDischarge Status
Alabama
Alaska
ArizonaYear, Month, HourYear, Month, Hour, Length of StayYes
ArkansasYear, Month, HourYear, Month, Hour, Length of StayYes
CaliforniaYear, QuarterYear, Length of StayYes
ColoradoYear, Month, Date, HourYear, Month, Day of Week, Length of StayYes
Connecticut
Delaware
District of Columbia
FloridaYear, HourYear, Length of StayYes
Georgia
HawaiiYear, MonthYear, Month, Length of StayYes
Idaho
IllinoisYear, QuarterYear, QuarterYes
Indiana
IowaYear, Month, DateYear, Month, Day of WeekYes
Kansas
KentuckyYear, Quarter, Length of StayYes
Louisiana
MaineDateDateYes
MarylandYear, MonthYear, Length of StayYes
MassachusettsYear, MonthYear, Length of StayYes
Michigan
Minnesota
Mississippi
MissouriYear, HourYear, Hour, Length of StayYes
Montana
Nebraska
NevadaYear, Month, HourYear, Month, Hour, Length of StayYes
New HampshireYear, HourYear, HourYes
New JerseyYear, Month, HourYear, Hour, Length of StayYes
New MexicoYear, Month, HourYear, Month, Hour, Length of StayYes
New YorkYear, MonthDateYes
North CarolinaYear, MonthYear, MonthYes
North Dakota
Ohio
OklahomaYear, Month, Day of WeekYear, Month, Day of WeekYes
OregonYear, Length of StayYes
PennsylvaniaYear, Day of Week, HourYear, Day of Week, Hour, Length of StayYes
Rhode IslandYear, MonthYear, Month, Length of StayYes
South CarolinaYear, Month, Day of WeekYear, Month, Day of Week, Length of StayYes
South DakotaYear, MonthYear, Length of StayYes
TennesseeDate, HourDateYes
TexasYear, Day of WeekYear, Quarter, Length of StayYes
UtahYear, Quarter, Length of StayYes
VermontYear, Length of StayYes
VirginiaYear, QuarterYear, Quarter, Length of StayYes
WashingtonYear, HourMonth, Hour, Length of StayYes
West VirginiaYear, Length of StayYes
WisconsinYear, Quarter, Length of StayYes
Wyoming



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