Economic burden of hypoglycemia: Utilization of emergency department and outpatient services in the United States (2005–2009)

Abstract

Objective: To estimate the economic burden of hypoglycemia on the healthcare system at the national level in the US between the years of 2005–2009.

Methods: This study analyzed the National Hospital Ambulatory Medical Care Survey (NHAMCS), including emergency department (ED) and outpatient department (OPD) components, and the National Ambulatory Medical Care Survey (NAMCS). The annual rates of ED and OPD visits associated with hypoglycemia were reported. Subsequent medical services after disposition were studied. The unit cost of specific medical service was estimated from the Medical Expenditure Panel Survey (MEPS). All annualized costs were adjusted to US 2009 dollars. We also estimated the rates of injury and ambulance use incurring within a visit for hypoglycemia.

Results: The total direct medical cost of hypoglycemia was estimated as $3.49 billion in 2005 and decreased gradually to $1.84 billion in 2009. The declining trend was correlated with hospital admissions from ED, which decreased from 170 665 in 2005 to 71,751 in 2009. Consequently, the estimated annual expenditure of hospitalization for hypoglycemia from ED declined over time by more than half ($2.90 billion in 2005, $1.25 billion in 2009). Injury was reported among 9.5% of the ED visits for hypoglycemia. Ambulances were used among 58% of the ED visits for hypoglycemia.

Conclusion: Hypoglycemia poses a significant burden on the healthcare system; however, annual direct medical cost of severe hypoglycemia in the US decreased over the 5 years studied, which is attributable to tremendous decrease in need of hospitalization following an ED visit.

Keywords:

• Hypoglycemia
• Diabetes mellitus
• Economic burden
• Emergency department
• Ambulatory care

Introduction

Diabetes mellitus is a major public health challenge with an estimated annual cost of $245 billion in 2012¹. Hypoglycemia—an acute complication of diabetes, remains the most challenging limiting factor to optimal management of diabetes. It also increases the morbidity, mortality, and economic burden of diabetes. The severity of an episode of hypoglycemia varies. Severe hypoglycemia (i.e. those episodes need assistance from others) may result in direct use of medical care². Patients with type 1 and type 2 diabetes both suffer from episodes of symptomatic hypoglycemia³. Although severe hypoglycemia is most common among type 1 diabetic patients with long disease duration, the risk rises with increasing duration of insulin therapy in patients with type 2 diabetes⁴. A total of 44.7% of study subjects reported minor hypoglycemia and 2.1% reported severe hypoglycemia events during a median follow-up period of 5 years in the ADVANCE study⁵. An annual prevalence of severe hypoglycemia may reach as high as 15% among insulin-treated type 2 diabetes⁶. A recent study reported the adjusted rate of severe hypoglycemia to be 11.21 per 100 person-years among patients with type 2 diabetes, who initiated basal insulin⁷.

The economic burden of hypoglycemia is better recognized nowadays, and encompasses a wide clinical spectrum⁸. Episodes of hypoglycemia that can be ameliorated by taking food, administration of glucose or glucagon by patients or their family members do not lead to significant medical cost; however, the estimated indirect cost due to lost productivity is still considerable⁹. Moreover, the increased numbers of these hypoglycemic events are associated with reductions in quality-of-life, increased fear and anxiety, and possibly decreased adherence to medications that leads to sub-optimal control of diabetes¹⁰. Severe episodes of hypoglycaemia, on the other hand, may require medical assistance including regular ambulatory visits, treatment by paramedics, or visits to emergency departments, which have been documented to cost the healthcare system significantly in several European countries^11,12. In the US, direct medical cost was estimated to be $188 (in 1996 US dollars) per episode of hypoglycemia that had used medical resources. Ginde et al.’s¹³ study analyzed the National Hospital Ambulatory Medical Care Survey (NHAMCS) and reported that hypoglycemia accounted for ∼5.0 million emergency department (ED) visits nationwide between 1993–2005, an average of 380 000 visits/year in the US, of which 25% resulted in hospital admissions. More recently, using published information, Foos et al.¹⁴ estimated the direct medical cost of severe hypoglycemia to be $1161 (in 2012 US dollars) per episode and $66 when only non-medical assistance was involved. Ambulance and hospital expenses represent the great majority of the costs related to hypoglycemia.

Understanding the use of healthcare resources associated with hypoglycemia is important to clinical practices and society for resource allocation. This study aimed to assess the national direct medical costs of hypoglycemia, including ambulatory visits, emergency department visits, and sequential inpatient care in the US.

Methods

Data sources

The emergency department (ED) component and outpatient department (OPD) component of the 1993–2009 National Hospital Ambulatory Medical Care Survey (NHAMCS) and the 1993–2009 National Ambulatory Medical Care Survey (NAMCS) were obtained and analyzed. The NHAMCS is designed to collect data on the utilization and provision of ambulatory care services in hospital emergency (NHAMCS ED) and outpatient departments (NHAMCS OPD) (http://www.cdc.gov/nchs/ahcd.htm). Findings are based on a national sample of visits to the emergency departments and outpatient departments of non-institutional general and short-stay hospitals. The NAMCS is a national survey designed to meet the need for objective, reliable information about the provision and use of ambulatory medical care services in the US (http://www.cdc.gov/nchs/ahcd.htm). Findings are based on a sample of visits to non-federal employed office-based physicians who are primarily engaged in direct patient care.

Definitions

In agreement of the method used in Ginde et al.’s¹³ study, we identified the hypoglycemia case based on ICD-9 codes of 251.0 (hypoglycemic coma), 251.1 (other specified hypoglycemia), 251.2 (hypoglycemia, unspecified), and 270.3 (leucine-induced hypoglycemia), in any of the three diagnosis fields. We included the ICD-9 code of 250.8 (diabetes with other specified manifestations), except when any of the following co-diagnoses were specifically coded: 259.8 (other specified endocrine disorders), 272.7 (lipidoses), 681.xx (cellulitis and abscess of finger and toe), 682.xx (other cellulitis and abscess), 686.9x (unspecified local infection of skin and subcutaneous tissue), 707.xx (chronic ulcer of skin), 709.3 (degenerative skin disorders), 730.0–730.2 (osteomyelitis periostitis and other infections involving bone), and 731.8 (other bone involvement in diseases classified elsewhere).

Emergency ambulance use was available in NHAMCS ED component for the time periods of 1993–1995, 1998–2000, and 2002–2009, and used for studying emergency transport among hypoglycemia ED visits. The disposition status variable in the NHAMCS and NAMCS (1993–2009) data was used to identify hospital admission. However, length of stay (LOS) was only available from 2005–2009 in the NHAMCS ED component. We herein estimated the economic burden of hypoglycemia in these 5 years. No inpatient care cost was estimated from the NHAMCS OPD and the NAMCS databases because of a lack of information on length of stay.

Demographic characteristics studied included age, gender, race, ethnicity, payment source, and region. Age groups were categorized into six groups, which were 0–19, 20–44, 45–64, 65–74, 75–84, and older than 85. Four census regions (Northeast, Middle West, South, and West) were identified for each visit. Racial groups were categorized into white, black/African American, and others. Ethnicity was dichotomized as Hispanic and non-Hispanic. Additionally, public insurance (Medicare, Medicaid/SCHIP, and state worker’s compensation), private insurance, self-payment, and others (no charge, unknown, and others) were used to indicate health insurance coverage.

Statistical analyses

Total number of visits to the ED, OPD, and ambulatory care associated with hypoglycemia and hypoglycemia rate (per 1000 visits) were calculated and reported in the total sample, and sub-groups of certain characteristics (i.e. age group, gender, region, race, ethnicity, health insurance status, and comorbidity). Admission rates (admission following ED visits for hypoglycemia per 1000 ED visits and admission following ED visits per 1000 ED visits for hypoglycemia) were computed, so was the associated length of stay. We also calculated the ambulance use rates (i.e. ED visits for hypoglycemia arrived by ambulances per 1000 ED visits and per 1000 ED visits for hypoglycemia). All measures were weighted to the national estimates with 95% Confidence Intervals (CIs), following the recommended methods by NHAMCS and NAMCS¹⁵. All data processing and analyses were done using SAS 9.2.

Economic estimates

Medical service utilization information of each visit is captured in the NHAMCS and NAMCS. Because no actual payment information was collected in the NHAMCS and NAMCS surveys, average cost was obtained using the national representative database, medical expenditure panel survey (MEPS, www.meps.ahrq.gov) for each specific type of medical service (i.e. ambulatory care, emergency department, and inpatient care) in the corresponding year. The total cost was then calculated by summarizing all medical services estimated from the NHAMCS and NAMCS multiplying by the unit cost of each type of service estimated from the MEPS in each year. The cost comprised the expenditure on ER visits and subsequent hospital admission from ED and outpatient visits for hypoglycemia. Hospitalization following OPD was not included due to the lack of information on LOS. All costs were adjusted to 2009 US dollars based on the consumer price index (CPI) medical service component from the US Bureau of Labor Statistics (www.bls.gov).

Results

NHAMCS ED component

Six hundred and twenty-one ED visits associated with hypoglycemia were recorded from 2005–2009, which were weighted to 2 369 963 visits at the national level. The rate of hypoglycemia among the visits to ED was 3.90 per 1000 visits. Table 1 presents the rates of ED visits associated with hypoglycemia in the years of 2005–2009 by socio-demographic characteristics of the patients; 38% of the visits were patients aged 65–84 years old; 69% who were white; 67% who had private insurance; and 42% who were in the South. Approximately 27% of the visits associated with hypoglycemia resulted in admission to hospital for 4.43 days (95% CI =3.81–5.06) on average. The majority of these ED visits associated with hypoglycemia were found to use an ambulance (61%).

Table 1. Hypoglycemia emergency department (ED) visit by sub-group (NHAMCS 2005–2009).

	Hypoglycemia rate per 1000 ED visits			Visits for hypoglycemia
	Rate	95% CI		Unweighted	Weighted	%
Total visits	3.90	3.35	4.45	621	2,369,963
Age group
0–19	0.60	0.34	0.87	31	98,008	4.14
20–44	2.32	1.80	2.83	130	528,137	22.28
45–64	5.64	4.52	6.76	205	715,341	30.18
65–74	13.96	10.34	17.58	122	508,055	21.44
75–84	11.64	9.19	14.09	99	393,230	16.59
85+	6.41	3.41	9.40	34	127,192	5.37
Gender
Female	3.91	3.31	4.52	335	1,289,798	54.42
Male	3.89	3.21	4.58	286	1,080,165	45.58
Region
Northeast	3.58	2.74	4.43	139	408,615	17.24
Middle west	4.02	2.93	5.11	129	554,226	23.39
South	4.04	2.94	5.14	223	985,506	41.58
West	3.78	2.94	4.62	130	421,616	17.79
Race
White	3.81	3.23	4.38	390	1,541,091	69.46
Black	4.86	3.79	5.92	171	640,927	28.89
Other	1.85	0.55	3.14	22	36,782	1.66
Ethnicity
Hispanic	3.14	2.27	4.01	62	229,022	11.14
Non-Hispanic	4.03	3.44	4.62	479	1,827,429	88.86
Health insurance
Public	2.48	1.94	3.03	157	503,863	22.10
Private	6.07	4.97	7.18	366	1,527,730	67.00
Self-pay	2.22	1.49	2.94	60	205,777	9.03
Other/unknown	2.03	0.60	3.45	11	42,705	1.87
Disposition
Admitted	7.60	5.92	9.27	161	631,141	26.63
Not admitted	3.32	2.81	3.82	460	1,738,822	73.37
Ambulance use
Ambulance use	14.68	12.64	16.71	364	1,389,970	60.54
Other transport	1.86	1.46	2.26	236	905,995	39.46

NHAMCS OPD component

Table 2 presents the rates of OPD visits associated with hypoglycemia in the years of 2005–2009 by socio-demographic characteristic of the patients. In aggregate, there were 420 370 visits associated with hypoglycemia, with the rate of 0.87 per 1000 visits; 37% were patient visits by those aged 20–44 years old, and 26% were by 45–64 year olds; whereas 19% were by 65–84 year olds; 67% of them were female, 67% white, 68% paid by private insurance, and equally distributed in four regions. There were only 0.18% of the OPD visits associated with hypoglycemia followed by hospital admissions.

Table 2. Hypoglycemia outpatients department (OPD) visit by sub-group (NHAMCS 2005–2009).

	Hypoglycemia rate per 1000 OPD visits			Visits for hypoglycemia
	Rate	95% CI		Unweighted	Weighted	%
Total	0.87	0.57	1.16	182	420,370
Age group
0–19	0.58	0.26	0.90	38	72,390	17.22
20–44	1.08	0.54	1.61	44	156,138	37.14
4–64	0.80	0.30	1.30	50	109,579	26.07
65–74	1.38	0.43	2.33	32	58,451	13.90
75–84	0.82	0.11	1.53	14	22,493	5.35
85+	0.16	0.00	0.33	4	1319	0.31
Gender
Female	0.96	0.52	1.39	96	283,360	67.41
Male	0.73	0.45	1.00	86	137,010	32.59
Region
Northeast	0.80	0.31	1.29	60	104,575	24.88
Middle west	0.70	0.32	1.07	48	106,338	25.30
South	0.68	0.07	1.30	41	97,466	23.19
West	1.90	0.65	3.14	33	111,991	26.64
Race
White	0.88	0.55	1.22	129	280,132	66.64
Black	0.99	0.17	1.82	35	102,127	24.29
Other	0.58	0.07	1.08	18	38,111	9.07
Ethnicity
Hispanic	1.49	0.47	2.51	31	100,849	25.88
Non-Hispanic	0.82	0.49	1.15	135	288,892	74.12
Health insurance
Public	0.45	0.19	0.72	52	79,107	20.01
Private	1.17	0.73	1.61	109	269,567	68.20
Self-pay	0.41	0.00	0.83	5	12,558	3.18
Other/unknown	1.05	0.00	2.52	10	34,008	8.60
Disposition
Admitted	0.26	0.00	0.58	3	745	0.18
Not admitted	0.87	0.57	1.17	179	419,625	99.82

NAMCS

We identified 115 visits to a physician office associated with hypoglycemia from 2005–2009, which weighted to 3 860 689 visits, nationally. Table 3 presents the socio-demographic characteristics of the patients and rates of hypoglycemia by socio-demographic characteristics. About 62% of the visits to a physician office associated with hypoglycemia were by patients aged 20–64 years old (29% in 20–44 and 35% in 45–64). The majority of the visits were by females (66%), whites (81%), and mainly in the South (32%) and West (31%). The main payment source was public insurance (65%), followed by private insurance (32%). Only 0.64% of the visits to the physician office associated with hypoglycemia were admitted into hospital.

Table 3. Hypoglycemia ambulatory care visit by sub-group (NAMCS 2005–2009).

	Hypoglycemia rate per 1000 ambulatory visits			Hypoglycemia visits
	Rate	95% CI		Unweighted	Weighted	%
Total	0.80	0.57	1.03	115	3,860,689
Age group
0–19	0.40	0.10	0.70	11	393,310	10.19
20–44	0.96	0.52	1.41	32	1,119,108	28.99
45–64	0.91	0.45	1.38	39	1,294,447	33.53
65–74	1.08	0.46	1.70	21	665,311	17.23
75–84	0.80	0.28	1.32	12	388,513	10.06
85+	n/a	n/a	n/a	n/a	n/a	n/a
Gender
Female	0.89	0.61	1.18	75	2,540,792	65.81
Male	0.66	0.35	0.98	40	1,319,897	34.19
Region
Northeast	0.64	0.19	1.09	16	578,879	14.99
Middle west	0.80	0.37	1.23	26	831,460	21.54
South	0.66	0.32	1.00	34	1,245,190	32.25
West	1.20	0.60	1.80	39	1,205,160	31.22
Race
White	0.71	0.46	0.97	68	2,392,803	80.68
Black	0.71	0.10	1.32	9	293,664	9.90
Other	1.48	0.00	3.11	10	279,253	9.42
Ethnicity
Hispanic	1.06	0.34	1.78	18	507,945	16.82
Non-Hispanic	0.74	0.49	0.98	70	2,511,794	83.18
Health insurance
Public	0.94	0.60	1.28	62	2,424,144	65.17
Private	0.68	0.41	0.96	38	1,194,796	32.12
Self-pay	0.14	0.00	0.40	4	27,365	0.74
Other/unknown	0.65	0.00	1.65	6	73,445	1.97
Disposition
Admitted	1.05	0.00	3.21	1	24,530	0.64
Not admitted	0.80	0.57	1.03	114	3,836,159	99.36

Economic outcomes

Table 4 presents annual costs associated with hypoglycemia due to visits to emergency department, including consequent inpatient care, and ambulatory care in years of 2005–2009. Unit costs, number of visits, and length of stay were also reported (Table 4). The expense of emergency department visit increased annually from $692 in 2005 to $932 in 2009. Despite the gradual increase in the unit cost, the annual expense of ED visits for hypoglycemia fluctuated between $339 million (in 2007) and $400 million (in 2006) due to the continuous decline in number of visits over the period of time. The unit cost of inpatient care was relatively stable during the time period, in the range of $3700 in 2008 and $4012 in 2007, based on the MEPS dataset. Approximately 72,000 in 2006 to 172,000 in 2009 admissions were estimated in the NHAMCS ED component, with a general declining trend. Consequently, the annual expense of inpatient care following an ED visit decreased from $2.89 billion in 2005 to $1.25 billion in 2009. The unit cost of ambulatory care increased slightly from $199 in 2005 to $229 in 2009 according to MEPS. The numbers of visits to ambulatory care (summation of NHAMCS and NAMCS) fluctuated between 0.37 million (in 2007) and 1.08 million (in 2008), which resulted in the annual expense of $80.46 million and $229.03 million, respectively.

Table 4. Direct medical cost of hypoglycemia (ED, inpatient care, and ambulatory care) by year.

	2005	2006	2007	2008	2009
Emergency Department
Unit cost ($/visit)	692.23	731.02	778.86	914.22	932.46
NHAMCS ED
Annual hypoglycemia visits	574,456	547,844	435,436	415,232	396,995
Estimated annual cost (2009 $)	397,654,428	400,484,899	339,143,035	379,612,502	370,181,958
Inpatient Care (Admitted from Emergency Department)
Unit cost ($/day)	3,896.84	3,839.37	4,011.76	3,699.57	3,973.43
NHAMCS ED
Length of stay	4.35	3.99	4.97	4.79	4.37
Annual hypoglycemia admissions	170,665	172,248	102,129	114,348	71,751
Estimated annual cost (2009 $)	2,892,986,051	2,638,682,998	2,036,291,620	2,026,351,452	1,245,876,407
Ambulatory Care
Unit cost ($/visit)	198.53	210.71	214.87	211.55	228.6
NHAMCS OPD & NAMCS
Annual hypoglycemia visits	1,004,860	417,535	374,477	1,082,648	981,169
Estimated annual cost (2009 $)	199,497,865	87,977,274	80,464,451	229,033,838	224,295,233
Total Annual Costs	3,490,138,344	3,127,145,170	2,455,899,106	2,634,997,792	1,840,353,598
Cost per Episode (2009 $)	2,209.91	3,239.29	3,032.30	1,759.15	1,335.37

Therefore, an annual direct medical cost associated with hypoglycemia declined from $3.49 billion in 2005 to $1.84 billion in 2009. In a similar pattern, the direct medical cost per episode of hypoglycemia (i.e. per encounter) was $3239 in 2006 and $1335 in 2009.

Discussion

To our best knowledge, this is the first study providing an empirical estimate of the economic burden of hypoglycemia at the national level in the US. Although the diagnosis codes used in this study are not specific to severe hypoglycemia, the coded episodes are plausibly severe ones that are of clinical importance to be recorded, especially at the ED setting. Direct medical cost attributed to hypoglycemia occurs in outpatient offices, emergency departments, and subsequent inpatient care and ambulance use. Our findings on the rates of hypoglycemia are consistent with the results of Ginder et al.’s¹³ study using the NHAMCS datasets in 1995–2003. From 1993–2009, there were a total of 6.89 million ED visits (or ∼400,000 annually) in the US (data not shown). We also expanded the investigation to ambulatory care using the two sources (the NHAMCS OPD and NAMCS). We further studied the impact of hypoglycemia on healthcare resource utilization associated with consequent inpatient care following a visit to the emergency department (27%), and also found a very high percentage of visits for hypoglycemia necessitating the use of ambulance transportation (61%). To avoid recurrent hypoglycemia, a hypoglycemic event requiring emergent medical care is a clinical red flag for diabetes management, which requires substantial interventions targeting on improving discharge plan, self-management such as dietary or medication adjustment, and close outpatient monitoring. All these statistics indicate the need to address the high burden of hypoglycemia on healthcare systems in the US.

This study provides the first estimation of national direct medical cost associated with hypoglycemia as high as $3.49 billion in 2005, ∼2–3% of the direct medical cost of diabetes in the US, which was estimated to be $116 billion in 2007¹⁶. It is not surprising that the majority of total costs are attributable to chronic complications such as cardiovascular diseases. The cost per hypoglycemic episode was as high as $3239 in 2006 and still $1335 in 2009. This is consistent with the modeled estimate from Foos et al.¹⁴ ($1161 per severe episode in 2012 USD), which indicates a continuous decline in the cost of hypoglycemia. The decline in the cost per episode is mainly due to the number of hospitalizations following the ED visits associated with hypoglycemia falling by almost 60% from 2006 to 2009. Consequently, the total hospitalization cost, which contributes to the majority of the total cost, is shown to be reduced by over half. On the other hand, the number of ambulatory care visits increased tremendously from 2007 to 2008, with the number of visits in 2009 being doubled compared to that in 2006. These changes may be explained by the improvement in awareness of hypoglycemia among primary care providers and patients since the findings of ACCORD study¹⁷. Given that insulin use remains at the same rate, if not greater, the effect of new anti-diabetic medications (e.g. GLP-1 agents, DPP-4 agents, and thiazolidinediones) with lower risk for hypoglycemia needs further investigation. The total annual medical encounters increased by 42%, while the total annual cost decreased by 41%. As a result, the cost per hypoglycemia-related episode (i.e. encounter) declined by 59% from 2006 to 2009. Cost per episode among patients with type 2 diabetes using insulin was calculated using claims data¹⁸, with an estimate of $1049 (95% CI = $426–$1672) per episode paid between 2001–2004 in a southeastern US managed care plan, and $1186 (range = $181–$4924) per episode between 1992–1998 in a large US mid-western health plan¹⁹. Rhoads et al.’s²⁰ analysis of the claims of 2664 employees of five large US companies with type 2 diabetes patients, who were on insulin from 1999–2001, found that the annualized medical expenditures directly related with hypoglycemia diagnosis were $3241.

Limitations

The results of this study should be interpreted with the consideration of the following limitations. First, our study focused on healthcare utilization and direct medical cost that attributes directly to hypoglycemia at the national level. The economic burden of hypoglycemia includes direct medical costs, and also indirect costs due to lost productivity, which significantly adds to the total economic impact of hypoglycemia. This indirect cost has been estimated to be as high as $579 per severe episode for patients with type 2 diabetes in Foos et al.’s¹⁴ study. ADA estimated that there was a total of $69 billion associated with reduced national productivity in 2012¹. Other consequences of hypoglycemia such as death and vascular diseases, both acute and long-term, may pose additional economic burden which are not assessed and documented in the literature^8,21. Also to be noted, inpatient care following an ambulatory visit was not included in the calculation due to the lack of information (i.e. LOS for each admission) in the data, which results in somehow conservative estimates because of the small number of admissions following ambulatory visits. Direct medical cost varies depending on the severity of the hypoglycemic episode that ranges from negligible (e.g. resolved by snacking) to severe (requiring assistance from third-party, non-medical or medical). Our study most likely identified severe episodes and provided the estimates of severe hypoglycemia. The identified hypoglycemic episodes did not distinguish between type 1 diabetes and type 2 diabetes, given there is no difference in the pathophysiology and treatment of hypoglycemia in either type. Cost estimates differ from country to country and between different healthcare systems based on the quality of service and the extent of treatment. Our results need to be interpreted with caution to generalize to other specific settings.

Second, the estimate of the cost of hypoglycemia also depends on the frequency of episodes. It is difficult to assess the absolute rate because of the lack of consensus of classification of hypoglycemia and under-reported self-treated episodes. The ICD-9 classification system is imperfect for case identification, as it was created for reimbursement rather than for epidemiological and economics research. The accuracy and completeness of the diagnosis codes may be an issue, especially in the emergency setting. However, the coding algorithm used has been validated and found a high level of accuracy compared to chart review²². Nevertheless, the medical resources identified in the study are more likely to be completely caused by hypoglycemia. It is likely that the rate of hypoglycemia is under-estimated for less severe episodes, which may result in an over-estimation of the cost per episode. Additionally, a limitation of the NHAMCS and NAMCS study design is that length of stay is only available for admissions from the ED, other data may be missed due to relying on medical records, and the cause of hypoglycemia is unknown. One of the limitations of these two surveys is the lack of individual patient’s identification information. It is, therefore, implausible to identify the frequency of any visit by a patient. Another limitation is the time lag of data availability in these national survey datasets, which may not be able to represent the most current information. Also, there might be reporting/definition issues in the data.

Lastly, the estimated MEPS unit cost, which is an average cost, regardless of the heterogeneity of service, is used to populate the direct medical costs in the US. In spite of the nature of the MEPS as a national representative sample of a non-institutionalized population, this approach of costing medical care may still introduce uncertainty in the cost estimates.

Conclusions

This study updates and characterizes the epidemiology and national trends in healthcare utilization of severe hypoglycemia using the NHAMCS and NAMCS database between 2005–2009. Using unit cost estimates from the MEPS, national direct medical cost contributed by hypoglycemia is estimated. This study quantifies the economic burden of hypoglycemia in the US, which shows a declining trend, yet costs significantly.

Transparency

Declaration of funding

This study was supported by the Bristol-Myers-Squibb investigator-initiated research program.

Declaration of financial/other relationships

LS has received grants/research funding from BMS. Fonseca V has received grant support from Asahi, Lexicon and Bayer; served as consultant to Intarcia, Merck, Glaxo Smith Kline, Novo Nordisk, Sanofi Aventis, Eli Lilly, Astra-Zeneca, Takeda, Jansenn,; given the expert testimony for Pfizer; owes stock/stock options from NuMe Health/Microbiome. JME peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

Some of the results were presented at ISPOR 18th Annual International Meeting, May 2013, New Orleans, LA, USA.