hospitalizations due to severe hypoglycemia in patients with type 1 diabetes mellitus: us national...

Hospitalizations Due to Severe Hypoglycemia

in Patients with Type 1 Diabetes Mellitus:

US National Perspective

Singh G, Mithal A, Mannalithara A, Sehgal A,

Bron M, Dabbous O, Peng X

ICORE

Stanford University

Takeda Pharmaceuticals

Disclosures

Supported by a grant from Takeda Pharmaceuticals

Drs. Bron and Peng are employees of Takeda

Pharmaceuticals

Dr. Dabbous is a former employee of Takeda

Pharmaceuticals

Type 1 Diabetes Mellitus in US

Type 1 Diabetes Mellitus (T1DM) affects >1 million Americans

In adults, T1DM constitutes approximately 5% of all diagnosed

cases of diabetes

Tight glycemic control using intensive insulin therapy significantly

reduces long-term microvascular and macrovascular

complications in T1DM (The Diabetes Control and Complications

Trial (DCCT))

U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2011. National diabetes fact sheet: national estimates and general information on diabetes and prediabetes in the United States, 2011. Available at http://www.cdc.gov/diabetes/pubs/pdf/ndfs_2011.pdf. Accessed August 29,2012.

Objective

To examine the prevalence and costs and payer

status of severe hypoglycemia hospitalizations

in T1DM patients in the US

Largest publicly available all-payer inpatient care database

20% stratified sample of all U.S. hospitalizations (1988 – 2011)

~5 to 8 million records of inpatient stays per year from about 1,000

hospitals representing ~85 – 96 % of all non–federal hospitals

Complex survey design with multistage strata and clustering

Strict quality-control and extensive validation

Methods and Data Nationwide Inpatient Sample (NIS)

2009 NIS: Represents 96% of US Population

NIS 2009

Year Data Sources Number of Hospitals

Number of Discharges in the NIS, Unweighted

Number of Discharges in the NIS, Weighted for National Estimates

2009 AR AZ CA CO CT FL GA HI IL IN IA KS LA KY MD MA ME MI MN MO MT NC NE NH NJ NM NY NV OH OK OR PA RI SC SD TN TX UT VA VT WA WI WV WY (Added NM and MT)

1,050 7,810,762 39,434,956

NIS: Data Characteristics

Over 100 clinical and non-clinical variables for each hospital

stay, for example:

Primary and secondary diagnoses

Primary and secondary procedures.

Admission and discharge status

Patient demographics (e.g., gender, age, race, median income for

ZIP Code).

Expected payment source

Length of stay and total charges

Hospital characteristics (e.g., ownership, size, teaching status)

Study Cohort

All inpatient hospitalizations in 2009 with primary or secondary

diagnosis of:

T1DM (ICD9 codes 250.x1, 250.x3), and

Hypoglycemia (ICD9 codes 250.8x, 251.0x, 251.1x, 251.2x) in

patients aged ≥18 years.

Denominator: 2009 US resident population (over 18

years): 232,637,3621

1 Estimated from US Census Bureau Data, 2010 census

Statistics

SAS ( Statistical Analysis System) version 9.3 procedure

PROC SURVEYMEANS used for calculating sample

statistics and appropriate variances based on data from

complex sampling designs

All estimates reported with 95% Confidence Intervals (CI)

Results

Total All-Cause US Hospitalizations (18 years

or older, 2009)

33.1 million in 232.6 million person-years

14,226 per 100,000 person-years

T1DM

326,395 All-Cause Hospitalizations (1%)

140 per 100,000 US population

Hypoglycemia in T1DM

20,839 hospitalizations (9 per 100,000 US pop)

6.4% of all T1DM hospitalizations

Total All-Cause US Hospitalizations (18 years

or older, 2009)

33.1 million in 232.6 million person-years

14,226 per 100,000 person-years

T2DM

7.2 million All-Cause Hospitalizations (21.7%)

3,100 per 100,000 US population

Hypoglycemia in T2DM

248,422 hospitalizations (107 per 100,000)

3.4% of all T1DM hospitalizations

Hypoglycemia Hospitalizations as % of All-Cause

T1DM and T2DM Hospitalizations

T1DM T2DM0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%6.4%

3.4%

Hypoglycemia Hospitalizations as a % of All-Cause

T1DM hospitalizations by Gender

Women Men5.4%

5.6%

5.8%

6.0%

6.2%

6.4%

6.6%

6.8%

7.0%

6.0%

6.8%

Gender

Mean Age at Admission with Diagnosis of

Hypoglycemia with T1DM

T1DM with Hypoglycemia Total T1DM T1DM without Hypoglycemia40.0

41.0

42.0

43.0

44.0

45.0

46.0

47.0

48.0 46.8

44.7 44.6

Hospitalization Type in T1DM Hypoglycemia

Most Hospitalizations are Non-Elective

2,486 (12%)

18,318 (88%)

ElectiveNon- Elective

Length of StayT1DM patients with hypoglycemia stayed longer compared to those

with all-cause hospitalizations

0

1

2

3

4

5

6

7

8

4.65.0

7.2

All-cause Hospitaliza-tions

Type 1 Diabetes hos-pitalizations length of stay

Hypoglycemia Hos-pitalizations in Type 1 DiabetesLe

ngth

of s

tay

in d

ays

Charges for Hospitalizations with Hypoglycemia in T1DM

(US$ per admission)

Hypoglycemia in T1DM T1DM All-Cause Hospitalizations$0

$5,000

$10,000

$15,000

$20,000

$25,000

$30,000

$35,000

$40,000

$45,000

$50,000 $46,039

$33,564$30,655

Charges

National Bill : Total Charges for Hypoglycemia

Hospitalizations in T1DM

Total hospitalizations = 20,839 (95% CI = 19,233 - 22,445)

Charge per hospitalization = $46,039 (CI = $42,144-$49,934)

Total charges = $ 959,406,721

As a comparison, hypoglycemia hospitalizations in T2DM :

Total hospitalizations = 248,422 (CI = 234,321-262,523)

Charges per hospitalization = $48,569 (CI = $45,781-

$51,357)

Total charges = $ 12.07 billion

Average Charge of US All-Cause Hospitalization: $33,232

Who is paying for T1DM Hypoglycemia

Hospitalizations ?Medicare and Medicaid are responsible for 64% of Payment

42%

22%

25%

7%4%

medicare

medicaid

private

self pay

other

Inpatient Case Fatality Rate in T1DM Hypoglycemia

Hospitalizations

Case-fatality in T1DM Hypoglycemia

284 deaths

Case-fatality = 1.36% (CI = 0.98-1.74%)

Case Fatality rate for all-cause T1DM hospitalizations

1.4% (CI = 1.3-1.51%)

Case Fatality rate for all-cause hospitalizations

2.2%

Limitations and Strengths

No unique patient identifiers.

Dependence on ICD9 codes.

No information on lifestyle factors or medications.

Charges vs. Costs

Study limited to adults 18 years or older

Nationwide sample of over 96% of all US population –

robust data.

Stratified, randomized sample from US hospitals - not a

“convenience” sample.

Future Work

Can we predict hypoglycemia?

Conclusions

Hypoglycemia in T1DM was associated with 20,839 hospitalizations

and 284 deaths in 2009, and a total cost of about $1 billion, most of

which is paid by Medicare and Medicaid.

While aggressive glycemic control remains important for patients,

the significant clinical and financial implications of severe

hypoglycemia should also be noted.

Careful selection of anti-diabetic drugs and close monitoring should

be considered to reduce the risk of severe hypoglycemia.

Development of novel anti-diabetics to reduce hypoglycemia while

maintaining glycemic control would be highly desirable.