3.1.1 Public hospitals

Acute public hospital activity data are collected and reported by the Economic and Social Research Institute of Ireland (ESRI, 2010). Specifically, the ESRI reports inpatient and day patient data on average discharges and length of stay by Australian Refined Diagnosis Related Groups (AR-DRGs) within a given year (2009 in the most recent publication). These data are collected from the Hospital In-Patient Enquiry (HIPE) scheme.

Acute public hospital activity data for the year 2009 (ESRI, 2010) contained 19 AR-DRG codes specifically related to eye conditions. These are AR-DRGs beginning with the letter C and relate to ‘diseases and disorders of the eye’. Not all 19 AR-DRGs, however, are associated with VI (e.g. C11Z eyelid procedures, C13Z lacrimal procedures). Following the UK cost-of-illness study (Access Economics 2009) the AR-DRGs were mapped, where relevant, to conditions associated with VI and blindness. The allocation followed (as closely as possible) the methodology used by Access Economics (2009) for UK Health Resource Groups (HRGs). It was determined that nine AR-DRGs were relevant to VI and blindness, and the eye conditions in this study. Table 3.1 presents the mapping by AR-DRG code, description and condition area assigned.

Table 3.1: AR-DRG mapping to eye condition within acute public hospital activity data

AR-DRG	Description	Assigned condition area
C02Z	Enucleations and orbital procedures	Other eye conditions
C03Z	Retinal procedures	DR
C04Z	Major corneal, scleral and conjunctival procedures	Refractive errors
C12Z	Other corneal, scleral and conjunctival procedures	Refractive error
C15A	Glaucoma and complex cataract procedures	Glaucoma/Cataract
C15B	Glaucoma and complex cataract procedures, same day	Glaucoma and cataract
C16Z	Lens procedures	Cataract
C61A	Neurological and vascular eye disorders with complications and comorbidities	AMD
C61B	Neurological and vascular eye disorders without complications and comorbidities	AMD

Source: Deloitte Access Economics’ analysis of ESRI (2010)

The ten excluded AR-DRGs were related to physical injury or complications of the eye and infections of the eye. Additionally the categories ‘other eye procedures’ and ‘other disorders of the eye’ were excluded as it could not be determined what proportion of these admissions were related to specifically to VI. The excluded AR-DRGs are listed below:

• C01Z: Procedures for penetrating eye injury,
• C05Z: Dacryocystorhinostomy,
• C10Z: Strabismus procedures,
• C11Z: Eyelid procedures,
• C11Z: Lacrimal procedures,
• C14Z: Other eye procedures,
• C60A: Acute and major eye infections with complications and comorbidities;
• C60B: Acute and major eye infections without complications and comorbidities;
• C62Z: Hyphema and medically managed eye trauma; and
• C63Z: Other disorders of the eye.

Average public hospital discharges and average length of stay (ALOS) in 2009 were reported for each AR-DRG (ESRI, 2010). These data cover both public and private patients treated in public hospitals. However, the average hospital cost per AR-DRG was not reported in the data and was not identified elsewhere. Therefore, the average hospital cost per bed day is estimated for each AR-DRG using 2008-09 Australian public hospital cost data (DoHA, 2009) and an adjustment for likely health care price differences between the ROI and Australia.

The average cost per bed day in 2008-09 in Australia was attained by dividing the average public hospital cost per AR-DRG separation by the ALOS for that separation (DoHA 2009). These costs were inflated to 2010 Australian dollars using average annual health inflation growth in Australia from 1997-98 to 2007-08, which was 3.4% per annum (AIHW, 2009). From these Australian data, the Irish costs per bed day for each AR-DRG were imputed using the approach applied in a global cost of dementia study (Wimo et al, 2006). Under this approach, differences between country health care unit costs (e.g. hospital care, pharmaceuticals) are assumed to be reflected by differences in Gross Domestic Product (GDP) per capita. Furthermore, differences in GDP per capita are assumed to also reflect differences in health care resource use, so countries with a higher GDP per capita utilise more costly resources, such as long-term care.

Following this method, average costs per bed day in the ROI were imputed using the ratio of GDP per capita between the ROI and Australia. On a purchasing power parity (PPP) basis, the GDP per capita ratio between the ROI and Australia is 1.05 (World Bank, 2010). Australian dollars were converted to euros at the average exchange rate in 2010 of €1 = $A1.44 (ECB, 2011).
Table 3.2 presents the costs per bed day for each DRG for the ROI and Australia.

Table 3.2: Average public hospital cost per bed day ($A and €) in 2010, selected AR-DRGs

AR-DRG	Description	Australia $A	ROI € (a)
C02Z	Enucleations and orbital procedures	$2,713	€1,979
C03Z	Retinal procedures	$2,817	€2,055
C04Z	Major corneal, scleral and conjunctival procedures	$2,422	€1,767
C12Z	Other corneal, scleral and conjunctival procedures	$2,500	€1,824
C15A	Glaucoma and complex cataract procedures	$2,505	€1,828
C15B	Glaucoma and complex cataract procedures, same day	$2,924	€2,133
C16Z	Lens procedures	$3,406	€2,485
C61A	Neurological and vascular eye disorders with complications and comorbidities	$1,207	€882
C61B	Neurological and vascular eye disorders without complications and comorbidities	$1,207	€881

Source: Deloitte Access Economics calculations using DoHA (2009), AIHW (2009) and World Bank (2010).

(a) Estimated by applying the ratio of PPP-adjusted GDP per capita (World Bank, 2010) between the ROI and Australia (1.05) to Australian costs, and then converting to euros at an exchange rate of €1 = $A1.44 (ECB, 2011).

Discharges in 2010, 2015 and 2020 were estimated by applying population growth for the ROI from 2009 onwards (CSO, 2008) to the number of discharges in 2009 data.

Discharges and ALOS for each DRG are presented in Table 3.3.

Table 3.3: ALOS and estimated discharges by year for selected AR-DRGs

AR-DRG	Description	ALOS (days)	Discharges 2010 (a)	Discharges 2015 (b)th>	Discharges 2020 ©
C02Z	Enucleations and orbital procedures	3.5	152	166	178
C03Z	Retinal procedures	1.4	8,705	9,500	10,199
C04Z	Major corneal, scleral and conjunctival procedures	4.6	153	167	179
C12Z	Other corneal, scleral and conjunctival procedures	2.5	278	303	325
C15B	Glaucoma and complex cataract procedures	3.8	368	402	432
C16Z	Glaucoma and complex cataract procedures, same day	1.0	510	557	598
C61A	Lens procedures	1.2	7,711	8,415	9,034
C61B	Neurological and vascular eye disorders with cc	6.2	164	179	193
C02Z	Neurological and vascular eye disorders without cc	2.1	744	812	872

Source: Deloitte Access Economics calculations using ESRI (2010) and CSO (2008).(a) Estimated by applying 2009-2010 ROI population growth of 2.0% to discharges in 2009 (ESRI, 2010). (b) Estimated by applying 2009-2015 ROI population growth of 11.4% to discharges in 2009 (ESRI, 2010). © Estimated by applying 2009-2020 ROI population growth of 19.6% to discharges in 2009 (ESRI, 2010).

The ROI costs per AR-DRG discharge presented in Table 3.2 were multiplied by the ALOS and total estimated discharges for each AR-DRG in 2010, 2015 and 2020 to attain total public hospital costs. Costs in 2015 and 2020 conservatively assume that public hospital costs per bed day and ALOS in 2010 remain constant.
Table 3.4 presents total public hospital costs by DRG. Overall, public hospital costs were estimated to be over €57.5 million in 2010. This is estimated to rise to nearly €67.4 million by 2020.

Table 3.4: Estimated public hospital costs (€) by selected AR-DRGs

AR-DRG	2010	2015	2020
Enucleations and orbital procedures	€1,053,158	€1,149,361	€1,233,969
Retinal procedures	€25,048,061	€27,336,145	€29,348,441
Major corneal, scleral and conjunctival procedures	€1,244,187	€1,381,360	€1,483,046
Other corneal, scleral and conjunctival procedures	€1,265,738	€1,381,360	€1,483,046
Glaucoma and complex cataract procedures	€2,558,400	€2,792,104	€2,997,639
Glaucoma and complex cataract procedures, same day	€1,088,449	€1,187,877	€1,275,320
Lens procedures	€22,991,088	€25,091,272	€26,938,316
Neurological and vascular eye disorders with cc	€897,121	€979,070	€1,051,143
Neurological and vascular eye disorders without cc	€1,375,878	€1,501,562	€1,612,096

Source: Deloitte Access Economics calculations using ESRI (2010), CSO (2008), DoHA (2009), AIHW (2009) and World Bank (2010).

3.1.2 Private hospitals

A limitation of the HIPE data is that it does not include patients treated in private hospitals. Further, no other data were identified reporting private hospital activity in the ROI.

Colombo and Tapay (2004) present the estimated proportions of public and private beds in public and private hospitals in the ROI. Their study estimates 78% of the total bed stock in the ROI to be within public hospitals and 17% within private hospitals (with 5% of total bed stock not allocated to either category). From these data, the ratio of private hospital beds to public hospital beds in the ROI is estimated to be 0.22 (17/78). This ratio is applied to public hospital expenditure (Section 3.1.1) to estimate private hospital expenditure for the same treatments/procedures. Using this approach it is estimated that private hospital activity for the AR-DRGs reported in Section 3.1.1 accounted for €12,536,864 million in private hospital costs in the ROI in 2010 (17/78 × 57,522,081).

One limitation of this method are that it assumes the cost per discharge for each AR-DRG to be the same in both public and private hospitals, whereas private hospitals may actually cost less (due to greater efficiencies) or more (due to higher fees). A further limitation is that it assumes the same mix of procedures to occur in public and private hospitals, whereas patients with no private health insurance may be more susceptible to certain types of eye disease. However, in the absence of private hospital activity data, this approach was used as a best proxy.

3.1.3 Estimated hospital expenditure by condition

Total public and private hospital expenditure on VI was estimated to be €70.1 million in 2010 (Section 3.1.1 and Section 3.1.2). The distribution of expenditure by eye condition (Chart 3.1) was estimated by applying the AR-DRG condition mapping presented in Table 3.1 to each AR-DRG (Section 3.1.1). This distribution assumes the same mix of hospital activity occurs in public or private hospitals.

It should be noted that 44% of hospital expenditure is associated with AR-DRG C03Z (retinal procedures). The large volume of activity in this DRG is unlikely to be solely associated with patients having DR, and may also include patients with AMD, cataract, and retinal detachment who undergo retinal procedures. However, in the absence of further data the conditions associated with the expenditure coded under AR-DRG C03Z can only be defined very broadly.