Cost-Effectiveness Analysis of Cataract Surgery: A Global and Regional Analysis

Article excerpt

Introduction

Cataracts are a major cause of blindness and of severe visual impairment leading to bilateral blindness in an estimated 20 million people worldwide. In developing countries 50-90% of all blindness is caused by cataracts (1).

A cataract is a clouding of the lens of the eye that causes loss of vision. Although cataracts result from many conditions, the most frequent cause is the natural ageing process. Other causes include injury, chronic eye disease and other systemic diseases, such as diabetes (2). Cataracts can take from a few months to several years to develop and can affect both eyes at the same time, but they often develop at different rates. Sometimes the cataract stops developing in its early stages and vision is only slightly impaired. But if it continues to develop, vision is impaired, and treatment is necessary. Surgery to remove the opacified lens is the only effective treatment for cataracts. Neither diet nor medications have been shown to stop cataract formation. There are several possible approaches for the surgical extraction of cataracts. In this paper we evaluate the cost effectiveness of two different surgical procedures delivered to 50%, 80% or 95% of those who need surgery.

Cost-effectiveness analysis can be undertaken in many ways, and there have been several attempts to develop methodological guidelines to make results more comparable. WHO has developed a standardized set of methods and tools that can be used to analyse the societal costs and impact on the health of the population of current and new interventions at the same time (3, 4). The WHO-CHOICE (CHOosing Interventions that are Cost-Effective) project is intended to provide regularly updated databases on the costs and effects of a full range of interventions to promote health and prevent disease, and to cure and rehabilitate. Additional information on the project is shown in Box 1 (web version only, available at: http://www.who.int/bulletin). Adopting this standardized approach to generalized cost-effectiveness analysis allows comparison to be made among a range of interventions relating to cataracts as well as with intervention for other major health problems.

Methods

Regions

It would be desirable to evaluate all possible combinations of interventions for every country in the world. In the case of some of the larger countries, it would be desirable to evaluate these combinations at a subnational level. No country has yet been able to do this, and many countries do not have the technical capacity to evaluate even a few interventions. At the other extreme, global estimates of an intervention's cost effectiveness are of little use to any specific country.

This study provides information on the costs and health effects of cataract surgery at the subregional level in different parts of the world. Regions are grouped by geographical proximity and epidemiological similarity (Box 2). These can then be further contextualized to the country level.

Box 2. Regions used in this study

Region                    Mortality stratum (a)

Africa                              D

Africa                              E

Region of the                       A
Americas

Region of the                       B
Americas

Region of the                       D
Americas

Eastern Mediterranean               B
Region

Eastern Mediterranean               D
Region

European Region                     A

European Region                     B

European Region                     C

South-East Asia Region              B

South-East Asia Region              D

Western Pacific Region              A

Western Pacific Region              B

Region                    Countries included

Africa                    Algeria, Angola, Benin, Burkina Faso,
                          Cameroon, Cape Verde, Clad, Comoros,
                          Equatorial, Guinea, Gabon, Gambia, Ghana,
                          Guinea, Guinea-Bissau, Liberia, Madagascar,
                          Mali, Mauritania, Mauritius, Niger,
                          Nigeria, Sao Tome and Principe, Senegal,
                          Seychelles, Sierra Leone, Togo

Africa                    Botswana, Burundi, Central African Republic,
                          Congo, Cole d'Ivoire, Democratic Republic of
                          the Congo, Eritrea, Ethiopia, Kenya,
                          Lesotho, Malawi, Mozambique, Namibia,
                          Rwanda, South Africa, Swaziland, Uganda,
                          United Republic of Tanzania, Zambia,
                          Zimbabwe

Region of the             Canada, United States of America, Cuba
Americas

Region of the             Antigua and Barbuda, Argentina, Bahamas,
Americas                  Barbados, Belize, Brazil, Chile, Colombia,
                          Costa Rica, Dominica, Dominican Republic, El
                          Salvador, Grenada, Guyana, Honduras,
                          Jamaica, Mexico, Panama, Paraguay, Saint
                          Kitts and Nevis, Saint Lucia, Saint Vincent
                          and the Grenadines, Suriname, Trinidad and
                          Tobago, Uruguay, Venezuela

Region of the             Bolivia, Ecuador, Guatemala, Haiti,
Americas                  Nicaragua, Peru

Eastern Mediterranean     Bahrain, Cyprus, the Islamic Republic of
Region                    Iran, Jordan, Kuwait, Lebanon, Libyan Arab
                          Jamahiriya, Oman, Qatar, Saudi Arabia,
                          Syrian Arab Republic, Tunisia, United Arab
                          Emirates

Eastern Mediterranean     Afghanistan, Djibouti, Egypt, Iraq, Morocco,
Region                    Pakistan, Somalia, Sudan, Yemen

European Region           Andorra, Austria, Belgium, Croatia, Czech
                          Republic, Denmark, Finland, France,
                          Germany, Greece, Iceland, Ireland, Israel,
                          Italy, Luxembourg, Malta, Monaco,
                          Netherlands, Norway, Portugal, San Marino,
                          Slovenia, Spain, Sweden, Switzerland, United
                          Kingdom

European Region           Albania, Armenia, Azerbaijan, Bosnia and
                          Herzegovina, Bulgaria, Georgia, Kyrgyzstan,
                          Poland, Romania, Slovakia, Tajikistan, the
                          Former Yugoslav Republic of Macedonia,
                          Turkey, Turkmenistan, Uzbekistan, Yugoslavia

European Region           Belarus, Estonia, Hungary, Kazakhstan,
                          Latvia, Lithuania, Republic of Moldova,
                          Russian  Federation, Ukraine

South-East Asia Region    Indonesia, Sri Lanka, Thailand

South-East Asia Region    Bangladesh, Bhutan, Democratic People's
                          Republic of Korea, India, Maldives, Myanmar,
                          Nepal

Western Pacific Region    Australia, Japan, Brunei Darussalam, New
                          Zealand, Singapore

Western Pacific Region    Cambodia, China, Cook Islands, Federated
                          States of Micronesia, Fiji, Kiribati, Lao
                          People's Democratic Republic, Marshall
                          Islands, Malaysia, Mongolia, Nauru, Niue,
                          Palau, Papua New Guinea, Philippines,
                          Republic of Korea, Samoa, Solomon Islands,
                          Tonga, Tuvalu, Vanuatu, Viet Nam

(a) A = Regions wish very low adult mortality and low child mortality;
B = low adult mortality and low child mortality; C = High adult it
mortality and low child mortality; D = High adult mortality and high
child mortality; E = Very high adult mortality and high child
mortality. …