|Year : 2012 | Volume
| Issue : 3 | Page : 214-222
Economic evaluation of iodine deficiency disorder control program in Sikkim: A cost-benefit analysis
Chandrakant S Pandav
Professor and Head, Centre for Community Medicine, All India Institute of Medical Sciences, New Delhi, India
|Date of Web Publication||3-Dec-2012|
Chandrakant S Pandav
Professor and Head, Centre for Community Medicine, Old OT Block, All India Institute of Medical Sciences, Ansari Nagar, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Iodine deficiency disorders (IDDs) are the most common cause of preventable brain damage globally. The strategy of prevention and control of iodine deficiency is based on iodine supplementation. Edible salt iodization and iodized oil injections are the two most commonly used vehicles for iodine supplementation. The objective of the study was to conduct a cost-benefit analysis of the two programs of iodine supplementation, i.e., iodized salt program (ISP) and iodized oil program (IOP) against no preventive program (NPP) option. Materials and Methods: The study was conducted in 1990 in the state of Sikkim in India. The costs were calculated on the assumption of universal coverage of ISP and coverage of IOP among all children aged 0-14 years and women in the age group of 15-44 years. Direct and indirect cost of ISP and direct cost of IOP was computed based on the costs of year 1991. The discount rate taken was 10% and all the costs were converted to the year 2010 using wholesale price index (WPI) data. Consequences in terms of health effects, Social/emotional effects, and resource use were included. Results: The discounted cost of ISP and IOP was Rs. 59,225,964 and Rs. 46,145,491, respectively. In ISP, 64.1% of the total cost was required for salt iodization, 17.6% for monitoring, and 18.3% for communication. In IOP, 50.9% of the costs were required for iodized oil; rest was for syringes and needles, manpower expenses, travel, and communication. Total resource saving was Rs. 95,566,220 for ISP and Rs. 92,177,548 for IOP. Incremental benefit for ISP was Rs. 36,340,256 and Rs. 46,032,057 for IOP. The cost-benefit ratio for ISP was 1.61 and 2.00 for IOP. Conclusion: IOP has a higher cost-benefit ratio for prevention of IDDs than ISP in the state of Sikkim, India.
Keywords: Cost-benefit analysis, Iodine deficiency disorders, Iodized oil, Iodized salt, Sikkim
|How to cite this article:|
Pandav CS. Economic evaluation of iodine deficiency disorder control program in Sikkim: A cost-benefit analysis. Indian J Public Health 2012;56:214-22
|How to cite this URL:|
Pandav CS. Economic evaluation of iodine deficiency disorder control program in Sikkim: A cost-benefit analysis. Indian J Public Health [serial online] 2012 [cited 2022 May 25];56:214-22. Available from: https://www.ijph.in/text.asp?2012/56/3/214/104242
| Introduction|| |
In India, 200 million people live in iodine-deficient areas; 71 million persons suffer from goiter, and other iodine deficiency disorders (IDDs). It is estimated that there are 2.2 million endemic cretins and 6.6 million individuals who have mild motor and mental impairment. 
The strategy of prevention and control of iodine deficiency is based on iodine supplementation. Edible salt iodization and iodized oil injections are the two most commonly used vehicles for iodine supplementation. The results of controlled trials with iodized salt in Kangra Valley, India and Guatemala, and iodized oil in Papua New Guinea have demonstrated prevention and reduction of endemic cretinism and endemic goiter by iodine supplementation. ,,,, A controlled trial with iodized oil in Zaire has shown reduction of perinatal and infant mortality and improvement in birth weight. , In a number of iodization programs, a reduction in stillbirths has also been reported.  Salt iodization has been accepted as the primary strategy for IDD control.
The current article is based on work done in the year 1990 in the state of Sikkim, India. The results of a population survey carried out in 1989 in the south district of Sikkim reported a goiter prevalence of 54.7%. The state government was planning to implement IDD control program in the state. The policy makers at the state level had the following two options to choose from based on existing knowledge; (a) a salt iodization program, (b) an iodized oil injection program. No information was available at that point of time on comparative advantages of the above-stated three approaches.
The authors carried out a study targeted toward enabling policy makers to identify the best approach in the context of IDD elimination in the state of Sikkim. The research question was whether from the viewpoint of the Society of Sikkim, an IDD control program using universal salt iodization or iodized oil to high risk group is preferable in terms of economic efficiency to a no preventive program? The study was conducted in 1990 and the results and findings of the study cannot be and should not be extrapolated to the present-day Sikkim state. We acknowledge this serious limitation of the article upfront. However, the methodology of the article is highly relevant and topical to the current practice of public health in India. The primary objective of this article is to share the methodology of the study and we hope that the detailed methodology will be helpful to the young researchers and wider public health fraternity of India.
| Materials and Methods|| |
General population of the state of Sikkim, India.
Cost-benefit analysis comparing three alternative programs targeted toward IDD elimination in state of Sikkim; (1) no preventive program (NPP), (2) iodized salt program (ISP), (3) iodized oil program (IOP).
Description of the Alternatives
NPP describes the current situation wherein there is no preventive program of iodine supplementation. ISP describes the situation when universal ISP is introduced and implemented in Sikkim. The salt iodization program will cover the entire population of Sikkim. IOP describes the situation when the iodized oil for iodine supplementation will be introduced and implemented in Sikkim. The population to be covered by the IOP is the high risk group of women in the child-bearing age group (15-44 years) and all children in the age group of 0-14 years.
Identification of Costs
ISP : The costs associated with the ISP are mainly related to the cost of salt iodization, monitoring and communication campaign [Table 1].
|Table 1: Identifi ed cost and consequences of iodine defi ciency disorders prevention program|
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IOP: The direct costs of IOP include the cost of iodized oil, the cost of disposable syringes and needles, the cost of personnel required for the program, the cost of transportation, and the cost of a communication program [Table 1].
Measurement of Costs
Salt iodization program
Salt iodization: The land and the building specifications were provided by the Ministry of Public Works, Government of Sikkim. The specifications required for the iodization plant and other details were provided by the Salt Commissioner to the Government of India and the Salt Consultant to UNICEF, WHO, and UNDP. One iodization plant with a capacity of 6 tons kg/h, can meet the requirements of the entire state, i.e., 4,000 tons.
Monitoring: A total of five iodine-monitoring laboratories (IML) will be established. Each laboratory would have one laboratory technician and one laboratory attendant. Assuming 200 working days in a year, a total of 4,000 salt samples would be analyzed in each of the laboratories every year. The costs include the capital cost of building, land and equipments and operating cost every year.
Communication Campaign: the cost of organizing one session of 1-day duration for an average primary health centers (PHC) would be the cost of time of the participants and the expenses required for organizing the session. It was estimated that 250 posters and 1000 leaflets would be required for a PHC.
Iodized oil program
In order to control IDDs IOP would be in operation "ad infinitum" and hence, costs for this program will be incurred in perpetuity. IOP has no capital costs and the operating costs are incurred only for the 1 st year of the 5-year injection cycle.
Iodized oil: the total eligible population for iodized oil injection in Sikkim is 241,808. The total requirement of iodized oil for Sikkim is 29,500 ampoules of 10 ml each taking into account about 25% wastage.
Disposable syringes and needles: the total requirement for Sikkim is 265,990 syringes and needles including 10% wastage.
Personnel: it has been estimated that 80 injections per day can be given by a team consisting of one doctor, one ANM, and one male health worker. With two-member teams, the total person-days for health workers required to cover the eligible population are 5,898.
Cost of transportation: as IOP would be a community outreach program; it would hire jeeps with drivers. Based on the average time required to cover the eligible population per PHC in each of the districts, the total number of days required per team would be 130 days for East district, whereas for the West and South would be 150 days with the North requiring 90 days.
Cost of communication campaign: prior to the injection program, a communication campaign will be carried out. The cost would be the same as for ISP.
Valuation of Costs
The reference year for the costs was 1991 and the discount rate assumed was 10%. All the costs were converted to the year 2010 using wholesale price index (WPI) data.
Salt iodization program
Salt iodization: the capital cost estimates of land and building have been provided by the Ministry of Public Works, Sikkim. The capital costs of salt iodization equipment and office equipment have been provided by the salt commissioner to the Government of India and the salt consultant to UNICEF, WHO, and UNDP. The capital costs were converted to equivalent annual costs (EAC) using the discount rate and the life of the equipment as estimated by the experts. The price of potassium iodate is 1,676 per kg delivered in Sikkim. Therefore, the total expenses required, including freight and handling, for 200 kg of potassium iodate is 335,200 per year.
Monitoring: The building, land, and equipments were valued on the market rate. The proportional salary of the involved personnel was used for training. The salary of laboratory personnel was based on the actual salaries being received by them. The actual costs of the chemical reagents and stationery were used.
Communication campaign: the proportional cost of salaries was used for estimating the cost of the initial meeting at the district level. The travelling and refreshment costs were added to this cost. The cost of a poster was assumed to be 67 and the cost of each leaflet was assumed to be 10.00.
Iodized oil program
Iodized oil: the cost of supplies required for IOP that are available in India were valued by the market prices in Sikkim. The cost of iodized oil which is imported from outside was valued by converting US dollar prices in Indian Rupees. (Exchange rate US $ 1=Rs. 26). The price per ampule of 10 ml is 302. The total cost of iodized oil for Sikkim is 8,899,266.
Disposable syringes and needles: In Sikkim, the price of one disposable syringe (1 ml) and needle is 7. The total cost of disposable syringes and needles then comes to 1,783,138.
Personnel: the costs of various personnel in the IOP are estimated on the basis of annual salaries. Since the analysis is carried out from the viewpoint of the Society of Sikkim, the per diem are not included. The daily salary assuming 200 working days in a year is 352 as per the existing salary structure in Sikkim. The total salary of health workers is calculated by multiplying person-days by 352. The total cost of health workers for 5,898 person-days is 2,075,791. A total of 28 Interns will be recruited for IOP. The Government of Sikkim will spend a total of 46,926 per Intern for their services in the IOP. Based on these estimates, the total cost for Interns is 1,313,940 for a period of 6 months.
Cost of transportation: Based on the experience of expanded program on immunization, the average expense of hiring a jeep with driver including petrol expenses for a day is 670. Thus, the total cost of transportation for the IOP is 2,493,806.
Communication campaign: will remain same as that for salt iodization program.
Identification of Consequences
Since the present analysis is carried out from the viewpoint of the Society of Sikkim, all the consequences to whomsoever they accrue are included. The consequences related to preventing IDDs are classified as given in [Table 1]. However, in the present analysis, only the consequences related to physical functioning and changes in resource use are included.
Measurement of Consequences
Health effects: Data was available only on the goiter prevalence in Sikkim. Data on endemic cretinism, mild motor or mental impairment and stillbirths and neonatal deaths attributable to iodine deficiency, were not available and were estimated from an epidemiological IDD model based on the goiter prevalence developed by Dulberg, et al. The prevalence of cretinism in Sikkim was estimated as 3.27%; the prevalence of mild motor and mental impairment is three times the prevalence of cretinism, i.e., 9.81%; and the incidence of ID-attributed stillbirths and neonatal deaths is 41.1 per 1,000 live births per year. Given the current population, presently in Sikkim, the total number of cretins is 13,200, the total number of people with mild motor and mental impairment was estimated to be 39,600 and the annual number of stillbirths and neonatal deaths attributable to IDD was estimated to be 552 per year.
In order to measure the health consequences of the program alternatives, a number of basic assumptions regarding the programs and the context in which they operate were made.
- After the iodine supplementation programs are introduced, the incidence of these IDD will be zero.
- Steady state population in Sikkim.
- IOP will be effective at the beginning of the year of implementation.
- This analysis will use the same discounting procedure as that of the cost scenarios and the same discount rate, 10%.
The incidence of the disease was estimated by the formula, Incidence = Prevalence/Duration, where duration is a life span (60 years). The prevalence of cretinism in Sikkim is 3.27%. Therefore, the incidence of cretinism in Sikkim is 0.0545% per year. Since a steady state population has been assumed; the incidence will be the same every year. Based on this incidence rate, for the total population of 403,612 in Sikkim, every year, a total of 220 cretins are added. Based on this incidence rate, every year a total of 660 people with mild motor and mental impairment are added to the population.
In ISP group, it was assumed that all new cases of IDDs would be prevented in all the age groups. The incidence of irreversible IDD will fall to zero after the implementation of IOP. That is, the effective coverage of IOP would prevent all the IDD related to iodine deficiency in the high risk group.
In order to compare the burden of goiter in the three alternatives, the concept of a common unit, i.e. visible goiter person years (VGPY) was introduced. The Sikkim IDD Survey reported goiter prevalence for five age intervals. The age/sex population distribution of India, which is used as a proxy for Sikkim, was available in 13, 5-year age intervals. The 13 age-specific prevalence rates were estimated by fitting a line on the available Sikkim data using a regression model. The visible goiter prevalence (VGP) for male and female subjects in each of the 13 five-year age intervals were used to estimate the VGP for age cohorts as they progress through the 60-year life of the program.
In the NPP scenario, the age distribution of goiter prevalence remains the same over time. For one entire generation of 60 years, the 12 five-intervals are summed up to obtain the total 678,197 discounted VGPY for males. The total number of discounted VGPY for females for 60 years is 821,279. Therefore, the total for males and females for one generation is 1,499,576 VGPYs. The estimates of NPP are used as the baseline for the analysis for assessing the effectiveness of the two prevention programs.
The decrease in VGP due to the salt program is estimated using data from Sooch and Ramalingaswani.  The study reported data on the reduction of VGP by 5-years age intervals at a 5-year follow-up. Therefore, the reduction in prevalence for the first 5-year follow-up period was used to model the reduction for each of the next 11 5-year follow-up periods.
Therefore under ISP, the total number of discounted VGPY for males, over one 60-year generation, is 385,099. The number of discounted VGPY for females is 341,945. Therefore, the total for males and females for one generation is 727,044 VGPY.
In IOP, only males in the age group 0-14 years and females in the age group 0-44 years are treated with iodized oil. Individuals outside these age ranges will become iodine-deficient as they become older. This was modeled into the analysis of VGPY. The total number of VGPY for males, over one generation of 60 years, is 524,321. The number of (discounted) VGPY for females is 366,631. Therefore, the total for males and females for the 60-year life of the program is 890,952 VGPY.
Treatment costs: The averted costs to the government health care system would be in the form of reduced treatment costs associated with prevented cases of IDD. As no published data were available on these issues, following assumptions were made:
- Based on the study done in Punjab, it was assumed that 10% of the population with health consequences related to IDD seek healthcare from government or private health sector. It was also assumed that physicians in the private sector provide the same healthcare services for IDD as the physicians in the government health sector.
- Information on the costs related to the existing management of IDD was collected by interviewing a convenient sample of four doctors from Sikkim in July 1991.
Costs for endemic cretinism: Based on the assumptions about physician cost (10 min @ 42,000/200 working days) and treatment cost of zero, the cost of management of each cretin was worked out as 4.50 per year. These are the additional lifetime costs for an endemic cretin. The total costs for management of endemic cretinism for a generation are the product of the discounted incidence of cretinism, 10% utilization rate, and 4.50.
Costs for mild motor and mental impairment: Since none of the population that has mild motor and mental impairment will seek care, there will be no costs averted for mild motor and mental impairment.
Costs for stillbirths and neonatal deaths: According to the information provided by the physicians, women who have stillbirths do not seek care at the health facility, therefore, for the purpose of the analysis, there will be no costs averted by this IDD.
Costs for endemic goiter: The total cost of management of one VGPY is the sum of the physician cost (20 mins @ 42,000/200 working days) and the medicine cost for 1 year. The physician cost is 9 per person per year whereas the medicine (thyroxine) cost is 43.80 per person per year. Therefore, the total cost for one VGPY is 52.80. The total cost of management of VGPYs for one generation is the product of discounted number of VGPYs in one generation multiplied by the cost for 1 year (Rs. 52.80) and the utilization of government and private health sector by the population (10%).
Productivity gains: The productivity gains (savings in lost work time) are measured by the human capital approach. These are related to:
- Productivity gain among individuals whose endemic cretinism, or mild IDD (motor and mental impairment), or endemic goiter are averted;
- Productivity gain due to a reduction in the requirement of full-time care givers for very severely impaired cretinous individuals.
In the absence of any data (published or unpublished), the measurement of productivity gain is estimated by interviewing two experts, using the author's experience and reaching a consensus.
It was agreed by the experts that the cretins would lead to an average productivity loss of 55%, and that mild motor and mental impairment would lead to an average productivity loss of 5%. If there is a full term-pregnancy that results in the death of a child (stillbirth or neonatal death), the family will later have another child. Therefore, the productivity gains for stillbirths and neonatal deaths that are prevented are not estimated in the present analysis.
For the purpose of the analysis, the experts agreed that the presence of a very severely impaired cretin individual, as defined by having 90 or 100% productivity loss, would require full-time care. Since the productivity potential of cretins is modelled in decile, 20% of cretin individuals would be in this category.
The presence of endemic goiter, on an average, will not interfere with the productivity of goitrous patients. Therefore, there will be no change in productivity related to endemic goiter.
Model Estimating Person-Years of Reduced Productivity
In order to estimate the productivity gains, first productivity loss in the presence of these conditions is estimated by a model that covers 60 years.
There is no productivity loss for endemic cretins for the first 14 years of age. In the 15 th year, there is one cohort of cretins who are now aged 15 years and ready to enter the work force. In the 16 th year, there are now two cohorts of cretins (age 15 and age 16) ready to enter the work force. Each year thereafter, the number of cohorts ready to enter the work force increases by one. The number of productive years lost for each cohort of cretin individuals' age 15 years or more is the incidence of cretinism per year multiplied by 0.55. The incidence of cretinism in Sikkim is 220 per year. The number of productivity years lost for each such cohort age 15 and above is 121 person-years (220 × 0.55). The number of person-years of lost productivity in the cohort is discounted at the rate of 10% per year over 60 years. Therefore, the total number of discounted lost person-years of productivity is 3,260 person-years.
The average productivity loss for individuals with mild IDD is estimated as 5% of the normal productivity. Using the same methodology, the total number of discounted lost person-years of productivity was estimated as 889 person-years.
The productivity gains for care givers are not included for the first 4 years because it is assumed that all children in the age group of 0-4 years require full time maternal care and supervision. In the 5 th year, there is one cohort of cretins now aged five who should no longer require such full time care and supervision. However, as discussed above, 20% of this cohort are severely impaired, and therefore would continue to require full time attention and supervision. Therefore, in each such household, one adult will be unable to enter the work force, because the adult must take care of this severely impaired individual. This is another form of reduced productivity. In the sixth and every succeeding year, as above, the number of cohorts entering (included) in the calculations increases by one. Using a similar methodology, the total number of discounted lost person-years of productivity was estimated as 3,530 person-years.
Valuation of Costs
The total working population of Sikkim was 48.3% of the total population as per the 1991 Census. The nonworkers constitute the remaining 51.7% of the total population. The population in the working age group was 15-59 years (53.9%). Therefore, 5.6% (53.9-48.3) of the total population was in the age group of 15-59 years but was not working. Using the prevalence of Cretinism (3.27%), we estimated that 1.8% (53.9×3.27) of the population in this age group would be cretins. As only 20% of the cretins would require full-time care giver, it means that 0.4% of the total population in the age group of 15-59 years would be expected to be severely impaired cretin individuals who are unable to enter the work force.
Thus, 5.2% (5.6-0.4%) of the total population who are not severely impaired cretins are not in the work force. It is thought that this 5.2% represents those persons who are students in the age group 15-19 years and severely disabled persons (other than severely impaired cretin individuals) who are unable to join the work force. A 5.2% of the total population being accounted for translates into 9.6% of the persons in the age group of 15-59 years. Therefore, the discounted number of lost person-years of productivity are reduced by 9.6% to take into account the 9.6% of the persons aged 15-59 years who would not work even if normal.
The productivity gain over one generation using a discount rate of 10% are calculated as Productivity gains = a × b × c × d
a = discounted lost person years of productivity
b = proportion of those in age group 15-59 years who are actually working (0.904)
c = minimum wage (Rs. 16 per day)
d = average number of working days in a year (183 days).
A sensitivity analysis was conducted with respect to the discount rate, the utilization rate, the duration of protection for iodized oil, and the price of iodine and iodized oil.
| Results|| |
Cost of iodized salt program
The total capital cost of the salt iodization plant in ISP was estimated to be 7,682,530. The annual equivalent cost of capital outlay of salt iodization was calculated to be 1,128,494. The total annual operating cost of salt iodization was 2,334,055. The total cost of salt iodization for "a given year" was 3,462,549 [Table 2].
|Table 2: Total cost of iodized salt program for "a given year" and cost of iodized oil program|
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The total cost of one monitoring laboratory was estimated to be 188,081 per year and for five laboratories it came to 950,462. The total cost for the communication campaign including the meetings, leaflets, posters and radio spots was estimated at 990,819 for the whole of Sikkim.
The total cost of ISP for "a given year" was 5,403,829. This is the cost that is applicable for any year of the program. The major portion of the cost is accounted for by the salt iodization (64.1%) with monitoring (17.6%) and communication (18.3%) sharing almost equally the remaining cost.
Cost of iodized oil program
The total cost of different components of IOP for Sikkim was estimated as 17,556,761 [Table 2]. In the IOP, all the costs are incurred at the beginning of the program, i.e., they occur at year 0. Based on the observations that iodized oil injection gives protection against IDD for 5 years, the annual equivalent cost for "a given year" of the program, using 10% discount rate for IOP works out to be 4,210,355.
The total discounted costs of ISP for one generation of 60 years is 59,225,964. The discounted costs for IOP for one generation of 60 years are 46,145,491.
The estimated impact of the different intervention on IDD is shown in [Table 3]. Since ISP will be implemented as a universal program, there will be a decrease in prevalence of goiterin all age groups, in male as well as female subjects. In addition, no new case of goitere would occur from the time of implementation. In IOP, goitere will be prevented only in the female subjects in the age group 0-44 years and in male subjects in the age group 0-14 years. Thus, it is estimated that in ISP 727,044 VGPY will occur, whereas in IOP 8,90,952 VGPY will occur. This means that due to ISP 772,532 VGPYs will be averted and with IOP 608,624 VGPYs will be averted.
|Table 3: Health effects of iodine defi ciency disorders for different alternatives|
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Applying the unit cost of management of VGPY and one endemic cretinism already estimated above at 206.72 and 17.63, respectively, to the total number of VGPYs and endemic cretinism averted, we get the total cost of management of IDD. However, assuming a 10% utilization of care, the costs are estimated. In the event of a no program (NPP), 31,006,834 will be incurred on the management of IDD, compared to 15,031,077 in ISP and 18,419,749 in IOP. The management costs averted are thus, 15,975,757 in ISP and 12,587,085 in IOP shown in [Table 4].
|Table 4: Cost benefi t of different iodine defi ciency disorders control programs|
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The productivity loss due to reduction in the requirement of full time care givers for very severely impaired cretin individuals was maximum and amounted to 36,589,476 for one generation. It constituted 46% of the total productivity loss. Similarly, the productivity loss for endemic cretinism was 33,787,233 (42.6%) whereas the productivity loss for mild IDD was 9,213,754 (11.6%). The total productivity gain for both the programs was 79,590,463 for one generation, discounted at 10%.
The total estimated resource savings (sum of management costs averted and productivity gains) for one generation for different alternatives are given in [Table 5]. The amount was 92,177,548 for IOP and 95,566,220 for ISP.
|Table 5: Total resource savings of different alternatives for one generation (Rs.)|
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The cost incurred in the two IDD control programs and the benefits accrued in monetary terms for one generation are compared in [Table 4]. Although both the programs are cost-beneficial, i.e., they are worth being implemented. The benefit cost ratio is better for IOP which reinforces the result of cost-effective analysis.
In summary, the IOP, both in terms of cost-effectiveness of irreversible and reversible IDDs, the primary and secondary outcome measure of IDD control programmes, as well as with respect to resource savings, is the preferred option.
The results of the analysis using 5% discount rate were more in favor of IOP. In order to equate the costs averted of ISP and IOP, the utilization rate of health services has to increase from the assumed rate of 10-45%. The results of the analysis remain unchanged with the assumption of 4-year protection with iodized oil: the IOP is more cost-effective than ISP. However, the difference had narrowed. The IOP, with 5-year duration of protection will cost less than ISP, even if the price of iodized oil increases by 20% whereas the price of iodine in ISP remains the same as the current price. However, if the duration of protection with iodized oil is assumed to be 4 years, and then even with a concurrent increase in price of 20% of iodized oil and iodine in ISP, the cost of IOP is more than that of ISP.
| Discussion|| |
The results of the analysis show that IOP has a higher cost-benefit ratio for prevention of irreversible IDDs than ISP in the state of Sikkim, India. The ISP was also had a favorable cost-benefit ratio but cost incurred per case of VGPY, endemic cretinism and death were marginally higher as compared to IOP. The present analysis addressed only the health effects related to physical functioning and resource savings in the form of costs averted. The effects of IDD on social and emotional functioning were not included. For the measurement of health effects, data were available only for goiter prevalence in the south district of Sikkim. The VGPY model appears to overestimate the increase in goiter prevalence in IOP for the cohort that graduates out of high-risk groups. The present analysis addressed only the costs averted to the government and modern private health sector utilization. The costs averted in traditional sector of medicine could not be identified due to data constraints and hence were not included. The other limitations for the measurement of the costs averted to the health care system were on the information on the current management of the IDDs in Sikkim. This was collected from a convenience sample of four physicians in Sikkim. Secondly, there was no information available on the utilization of health services in Sikkim. Information on utilization of health services (10% utilization for government and private health sector) from the only published study in India was taken.
The present analysis contributes to our knowledge in the area by its comprehensive identification, measurement and valuation of costs and consequences related to IDD. There have been only two studies that have attempted economic evaluation of IDD. One of them was limited to an evaluation of the effects of iodine prophylaxis on moderate intelligent quotient retardation among children in Ecuador.  The second study, using the same data from Ecuador, attempts to assess the overall effect of a 20% reduction of cretinism on per capita income. 
There are operational difficulties in the implementation of iodized oil injection program. Availability of trained health manpower to administer injections is one of the serious hindrances for implementing IOP. ISP, on the other hand, with its population approach does overcome some of the limitations of IOP. However, ISP also has several bottlenecks like setting up of infrastructure for iodizing salt, resistance of population to change the type of salt they are consuming, etc. In this study, we have only factored in the cost of both interventions. The program level and operational issues between the two options of iodized salt and iodized oil need to be further explored in such high-risk settings.
In severe endemic iodine deficiency areas, such as Sikkim, the incidence and prevalence of irreversible IDD's is very high. It is an emergency situation. The experience from different parts of the world, primarily from developing countries and in India over last 40 years has demonstrated that organization of an effective salt iodization program takes time to get the program in place. Therefore, in view of the severe iodine deficiency as well on the grounds of economic efficiency, the IOP for Sikkim is suggested as an interim emergency measure. The IOP can be organized in a short time to cover the high-risk population and prevent further occurrence of irreversible IDD's. The IOP will also give a lead time of 5 years. Depending on the reduction of IDDs, the situation would need a reassessment. During this period, necessary steps to organize effective salt iodization program can be initiated. These recommendations are specific for severe endemic areas like Sikkim and cannot be generalized to other situation of lower endemicity. There are problems for which the solution is a matter of knowhow and there are problems for which the solution is a matter of will. IDD is a good example of a major nutritional disorder for which the techniques of prevention and control are available and appear affordable. All it takes is a strong will, wider awareness, and cooperation among those who hold a key to the solution of this problem. The additional information and research issues should not delay the implementation of interventions.
| Acknowledgments|| |
This work is dedicated to late Roberta Labelle (1957-1991), Assistant Professor, Centre for Health Economics and policy Analysis, McMaster University. She inspired and made me love Health economics through her high standards, commitment, and brilliance. I am greatly indebted to Professor Jeremiah Hurley, my preceptor, who guided me during this thesis.
I am grateful to the Department of Clinical Epidemiology and Biostatistics for their support. I am particularly grateful to my thesis committee: Professor Bernie O'Bernie, John van der Meulen, Pete Rosenbaum, and to Dr. David Evans for their encouragement and patience. I would also like to thank Dr. Kapil Yadav, Dr. Stalin P, and Dr. Rakesh Kumar for their assistance in compiling this manuscript.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]
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