Thạc Sĩ Improving equitable access to cataract surgery in rural southern china: Using willingness to pay dat

Đề tài: IMPROVING EQUITABLE ACCESS TO CATARACT SURGERY IN RURAL SOUTHERN CHINA: USING WILLINGNESS TO PAY DATA TO ASSESS THE FEASIBILITY OF A TIERED PRICING MODEL TO SUBSIDIZE SURGERIES TO THE POOREST
TABLE OF CONTENTS

1 STUDY AIM AND OBJECTIVES 1

1.1 OBJECTIVE 1 3

1.2 OBJECTIVE 2 3

1.3 OBJECTIVE 3 4

2 BACKGROUND 5

2.1 EPIDEMIOLOGY OF CATARACT AND CATARACT SURGERY 5

2.2 RURAL HEALTH CARE IN CHINA 6

2.3 HKI, CHINA AND TIERED PRICING 10

2.4 THE ARAVIND EYE HOSPITAL, INDIA 11

2.5 HKI, CHINA AND CATARACT SURGERY 13

3 CONCEPTUAL FRAMEWORK 14

3.1 DEFINING EQUITY IN TERMS OF WILLINGNES S TO PAY 14

3.2 SOCIAL WELFARE AND THE EQUITY-EFFICIENCY TRADE-OFF 16

3.3 THE ECONOMICS OF TIERED PRICING 18

4 CONTINGENT VALUATION AND WILLINGNESS TO PAY 20

4.1 CONTINGENT VALUATION 20

4.2 WTP AND 'DEMAND ' 23

4.3 WTP AND SOCIAL WELFARE 25

4.4 WTP AND EXTERNALITIES 27

4.5 WTP AND ALTRUISM 29

5 THE USE OF WTP IN DEVELOPING COUNTRY RESEARCH 31

5.1 WTP FOR INSECTICIDE TREATED BEDNET S IN EASTERN NIGERIA 31

5.2 WTP FOR COMMUNITY-BASED INSURANCE IN BURKINA FASO 32
5.3 WTP FOR CATARACT SURGERY IN NEPAL 33

5.4 WTP FOR CATARACT SURGERY IN TANZANIA 33

5.5 FINDINGS AND IMPLICATIONS 34

5.6 BEST PRACTICE FOR WTP SURVEY ADMINISTRATION 37

6 DATA COLLECTION 42

6.1 SAMPLING FRAMEWORK 42

6.2 SAMPLE SIZE 43

6.3 SURVEY DESIGN 44

6.4 SURVEY ADMINISTRATION 50

7 STATISTICAL METHODS 53

7.1 CATEGORICAL OUTCOME S - INTERVAL REGRESSION 53

7.2 CONCENTRATION CURVE AND INDEX ESTIMATION 58

8 RESULTS 63

8.1 SAMPLE SIZE AND RESPONSE RATE 63

8.2 SAMPLE CHARACTERISTICS 65

8.3 BIVARIATE ASSOCIATIONS WITH WTP ANYTHING FOR CATARACT SURGERY 75

8.4 MAXIMUM WILLINGNES S TO PAY FOR CATARACT SURGERY 79

8.5 OBJECTIVE 1 PATIENTS WILLINGNES S TO PAY 86

8.6 OBJECTIVE 2 CAREGIVERS WILLINGNES S TO PAY 99

8.7 EQUITY OF ACCES S USING CAREGIVER' S WTP 104

8.8 OBJECTIVE 3 WILLINGNESS TO PAY FOR AMENITIES 105

9 DISCUSSION 109

9.1 FACTORS AFFECTING PATIENT' S WTP 109

9.2 PATIENT' S WILLINGNESS TO PAY 113

9.3 FACTORS AFFECTING CAREGIVER' S WTP 115
9.4 HOUSEHOLD CHARACTERISTICS' IMPACT ON WTP ON PAIRED RESPONDENTS 116

9.5 CAREGIVERS' PREDICTED WILLINGNES S TO PAY 118

9.6 EQUITY OF ACCES S 122

9.7 POLICY IMPLICATIONS FOR HKI 124

9.8 POLICY IMPLICATIONS FOR CHINA' S RCMS 127

9.9 WA S THE METHODOLOGY APPROPRIATE FOR OUR OBJECTIVES? 128

9.10 WA S THE METHODOLOGY APPROPRIATE FOR THIS POPULATION? 128

9.11 BEST PRACTICE FN PRACTICE 133

9.12 STUDY LIMITATIONS 137

9.13 CONCLUSION 140

10 APPENDICES 151

10.1 WTP SURVEY FOR PATIENTS 151

10.2 WTP SURVEY FOR CAREGIVERS 171

11 CURRICULUM VITAE - ELAINE MONISOLA BARUWA 190

1 Study Aim and Objectives

This study was designed to evaluate whether access to cataract surgery is equitable in the

Guangdong Province of the People's Republic of China (PRC) and to explore the feasibility

of using a tiered pricing model to increase uptake by the poorest, using data from a

willingness to pay survey administered to a rural population in this region.

China and Cataract

Cataract is the leading cause of blindness in the PRC in people aged 50 and over.

Prevalence rates of cataract blindness have been estimated to be up to 4.37%, with rates of

low vision being even higher in this age group (Hsu, Cheng, Liu, Tsai, & Chou, 2004; Li, Xu,

He, Wu, Munoz, & Ellwein, 1999a). Combined with a low cataract surgery rate of 230 per

million per year the result is that China has a severe burden of curable blindness and low

vision (Apple, Ram, Foster, & Peng, 2000).

Helen Keller International, Chin a

Helen Keller International (HK.I), in conjunction with the privately owned Guangming Eye

Hospital (GEH) and the Yang Jiang local government health department set up a cataract

screening and surgery program in 2001 . The program now provides about 1800 surgeries a

year which translates roughly to a rate of at least 720 per million if we do not include the

surgeries performed by other providers. A cross sectional willingness to pay study conducted

three months after the program began, suggested that income would be a limiting factor for

access to cataract surgery even with the service priced at cost (He M et al., 2007) . Now the

program would like to determine whether or not it is feasible to use a tiered pricing structure

to increase its revenues in order for it to provide cataract surgery at a lower price to those
unable to pay the current fee of 500 - 630 Renminbi (RMB) where 1 US$=8RMB.

Access : Inequality and Inequity

In the 200 1 study it was found that there were significant differences in the amount that

respondents were willing to pay across income groups, specifically, those in higher income

groups were willing to pay higher amounts. This finding highlights an inequality in

willingness to pay that is not necessarily inequitable - there is nothing 'unfair' about

individuals with a higher income being willing to spend more than individuals with lower

income. However it was also found that only 37% of the respondents would be willing to pay

500RMB or more to obtain cataract surgery. This result suggests that even though the service

is now available to this population, there may remain access limitations for some individuals

due to the pricing and this outcome is inequitable. The combination of these findings suggests

that, with enough income variation, it might be possible to induce those with higher incomes

who may be willing to pay more for surgery, to actually do so and then to use the increased

revenue to subsidize a lower price that improves access for those with lower incomes and

willingness to pay. In other words we could take advantage of an existing income inequality

and provide somewhat unequal services to reduce an access inequity for the most basic level

of service.

This study will utilize data from a willingness to pay survey to obtain a valuation of

cataract surgery by respondents and their caregivers which, when combined with the known

prices, will determine whether or not access is equitable. It will then determine whether or

not a large enough number of respondent s value additional amenitie s highly enough to enable

higher pricing. Such amenities could include having a senior surgeon perform their surgery,

having an improved intra-ocular lens implanted or having food and transport provided for
them. With estimates of revenue, a range of possible subsidized prices can be determined and

used to predict the impact of the model on the equity of access to cataract surgery.

1.1 Objective 1

To determin e whethe r access to cataract surgery is equitable in this population
using willingness to pay survey dat a from respondents wit h cataract

Empirical Analysis : The results from a survey administered to respondents who are

cataract blind in at least one eye will be used to explore how willingness to pay for cataract

surgery may differ by demographic and socioeconomic characteristics, vision status and

potential sources of payment. Following this exploration, an appropriate model to estimate

willingness to pay will be proposed and tested. From these results an 'incidence rate' for

cataract surgery at current pricing levels will be determined and combined with the income

data to construct a concentration index that describes the equity of access.

1.2 Objective 2

To determin e whether willingness to pay differs between respondents with
cataract and their households/caregivers and what impact this has upon the
willingness to pay estimates

Empirical Analysis : The results from a survey administered to the caregivers who

accompany respondents will be used to explore how willingness to pay for cataract surgery

may differ between patients and another member of their household and to determine how

much care the patient needs because of their impaired vision. Specifically this comparison

will be used :

l) To determine why there may be differences in WTP from respondents who come from
the same household and are subject to the same income constraint. It could be important if

sources other than own savings and insurance are used to pay for surgery

2) To determine if there are intergenerational differences in the perceived need for surgery

3) To determine whether there are differences in perceived control of household resources

4) To determine whether a societal valuation of cataract surgery might be significantly

higher or lower than the patients' valuation of cataract surgery

1.3 Objective 3

To estimate the revenue that can be expected from a tiered pricing model and
to determin e the potential of the model to improve equity of access to surgery

Empirical Analysis : The willingness to pay data will be used to assess the potential

demand for the additional amenities that GEH/HKI could provide at minimal cost. These

amenities are having a senior surgeon perform the surgery, an improved intraocular lens,

transport to/from the clinic and the provision of meals. Subsequently, the projected revenue

from the provision of such services will be estimated and used to determine the feasibility of a

tiered pricing and cross subsidization model. To avoid having to determine patients' choices

between amenities, revenues will be determined from the provision of a single amenity at a

time. Finally a concentration index will be estimated at each feasible subsidized price to see

what impact this model may have on the equity of access.