eFigure. Cataract Surgery and Postoperative Visit Schedule for Immediate Sequential Cataract Surgery and Delayed Sequential Cataract Surgery: Noncomanaged and Comanaged
eTable 1. National Cataract Surgery Volume Estimate Based on Ambulatory Surgery in the United States, 2006 Report
eTable 2. Demographic Data Summary
eTable 3. Patient Driving Cost Comparison Between ISCS and DSCS: Adjusted for Noncomanaged and Comanaged
eTable 4. Sensitivity Analysis Plus 1 Standard Deviation: Patient Driving Cost Comparison Between ISCS and DSCS: Noncomanaged and Comanaged
eTable 5. Sensitivity Analysis Minus 1 Standard Deviation: Patient Driving Cost Comparison Between ISCS and DSCS: Noncomanaged and Comanaged
eSensitivity Analysis 1. Sensitivity Analysis of Lost Production West TN (Maximum)
eSensitivity Analysis 2. Total West TN Patient Cost Reduction Sensitivity Analysis (Minimum and Maximum): Note: Facility Used Was ASC in Direct Costs
References in eSupplement. Supplemental References
Neel ST. A Cost-Minimization Analysis Comparing Immediate Sequential Cataract Surgery and Delayed Sequential Cataract Surgery From the Payer, Patient, and Societal Perspectives in the United States. JAMA Ophthalmol. 2014;132(11):1282-1288. doi:10.1001/jamaophthalmol.2014.2074
The cost difference is evaluated between delayed sequential cataract surgery (DSCS) and immediate sequential cataract surgery (ISCS) in the United States for patients covered by Medicare.
To perform a cost-minimization analysis comparing ISCS with DSCS in the United States from the payer, patient, and societal perspectives for the West Tennessee region and nationally.
Design, Setting, and Participants
A cost-minimization analysis using cataract surgery volume and eligibility estimates, 2012 Medicare reimbursement schedules, and actual or estimated patient cost data for the West Tennessee region and nationally was performed comparing ISCS with DSCS. The West Tennessee model was set in a mixed small city and rural private practice setting and was extrapolated to a national model. Ambulatory surgery center and hospital outpatient department setting costs were evaluated.
Main Outcomes and Measures
West Tennessee and national Medicare payer costs per patient and the total national Medicare payer cost for DSCS and for ISCS, as well as West Tennessee and national Medicare patient (direct medical, travel, and lost wages) costs for DSCS and for ISCS.
Nationally, Medicare was estimated to reduce costs by approximately $522 million with the switch from DSCS to ISCS in 2012. With a change to ISCS, a West Tennessee Medicare patient was estimated to reduce costs by $174 for direct medical costs, $40 for travel costs, and $138 for lost wages (total cost reduction range, $329-$649). The total Medicare-based societal cost reduction was $783 million.
Conclusions and Relevance
Payers and patients would benefit from an economic standpoint by switching from DSCS to ISCS. Patients and their families would benefit from fewer visits. This becomes important given the increasing number of future cataract surgical procedures that will be performed as the baby boomer generation ages, especially given the fact that Medicare is already financially strained. Further research is needed to evaluate the effect of switching to ISCS from the physician and surgical facility perspectives.
Modern cataract surgical techniques involve topical anesthesia, small self-sealing incisions, foldable intraocular lenses, and antibiotic prophylaxis regimens that have improved surgical outcomes and provided faster visual rehabilitation.1 These improvements have led to the controversial subject of immediate sequential cataract surgery (ISCS), and whether cataract surgical procedures on both eyes should be performed at the same surgical visit but as separate independent procedures (with one immediately after the other), or whether delayed sequential cataract surgery (DSCS) should be performed with cataract surgery performed on one eye at a time (with a period of days to months between the 2 eye surgical procedures). Delayed sequential cataract surgery is the current standard of care in the United States. Performing ISCS is controversial, but current standard practice in the United States includes performing bilateral corneal refractive surgery, bilateral eye muscle surgery, and bilateral lid surgery.2 Retina specialists are commonly performing bilateral intravitreous injections. Immediate sequential cataract surgery is widely practiced in other countries such as Sweden, Finland, and Spain.3,4
A primary concern in comparing DSCS and ISCS is whether the 2 procedures have a similar safety profile. To reduce the risk of bilateral complications, certain surgical practices must be implemented, including treating the 2 procedures as separate surgical procedures by using a different set of sterile instruments and different lot numbers of solutions, changing gloves and gowns between eyes, and prepping each eye as a separate surgical procedure.1,5- 9 Multiple studies6,8,10,11 found that ISCS was associated with no increase in intraoperative or postoperative complications compared with DSCS. Several prospective nonrandomized and randomized clinical trials1,9,12 compared ISCS with DSCS and found equivalent safety outcomes.
A second important concern is whether ISCS and DSCS are equally effective in refractive results, visual outcomes, and patient satisfaction. Prospective clinical trials1,7,9 comparing the refractive results of ISCS and DSCS found that the refractive outcomes were equivalent between the 2 groups: the studies compared ISCS and DSCS in terms of visual function and patient satisfaction using Visual Function 7, Visual Function 14, and Cataract Symptoms 5 scores and found no difference in visual function or patient satisfaction between the groups after surgical procedures on both eyes had been completed. An economic analysis in Finland found that surgical outcomes and patient satisfaction were similar in ISCS and DSCS groups and noted that “[b]ecause of equal effectiveness, the cost-effectiveness analysis turned into a cost analysis.”12(p1005)
Few economic studies12- 14 have compared ISCS with DSCS, and no US-based analyses were found to date. The international data used hospital cost models, and this article tried to fill in the gaps by considering the payer, patient, and societal perspectives in the United States. The surgical facility component of this study focused on ambulatory surgery center (ASC) and hospital outpatient department (HOPD) models in a private practice setting. Given that previous studies1,7,9,12 have shown equivalent efficacy between ISCS and DSCS, a cost-minimization analysis comparing ISCS with DSCS in the United States was performed to evaluate the economic cost and potential policy implications from the payer, patient, and societal perspectives.
The London School of Economics and Political Science, London, England, reviewed and approved the protocol for this study as part of the master’s thesis review process. No institutional review board approval was needed. This cost-minimization analysis comparing ISCS and DSCS used the West Tennessee region (hereafter West TN) as the basis for the model. Physicians Surgery Center, Jackson, Tennessee, a multispecialty ASC (hereafter the ASC) provided some of the modeling data. The model also used data gathered from Eye Clinic, PC, Jackson, Tennessee (hereafter the eye clinic), a specialty ophthalmology single practice. Both of these entities serve a mixed small city and rural population. Both orally consented to the use of their data in this analysis. This model was extrapolated to approximate national payer and patient perspectives.
Medicare pays for approximately 80% of the cataract surgery in the United States and was chosen as the payer in this study.15,16 The 2012 Medicare surgeon fees for West TN and the national mean for standard cataract surgery (Current Procedural Terminology code 66984) were obtained.17,18 The West TN 2012 Medicare reimbursement for ASCs was obtained from the ASC, and the national ASC and HOPD 2012 Medicare reimbursement schedules were procured.18 The 2012 Medicare anesthesia fees were obtained for West TN and the national mean.19,20 The Medicare fees for the surgeon and surgical facility were adjusted for the 50% reduction in Medicare payment for the surgical procedure on the second eye if it was performed in the same surgical setting.
The West TN Medicare cataract surgery volume obtained from the ASC showed that 1598 Medicare cataract surgical procedures were performed in 2011. The national 2011 Medicare cataract surgical volume had to be estimated because specific volume numbers were unavailable. The 2006 data on ambulatory surgery in the United States were used to obtain a total estimate of Medicare cataract surgical procedures performed nationally.21
The prevalence of complex cataract surgery (Current Procedural Terminology code 66982) was determined from the ASC cataract surgery data. It comprised 9.3% of cases and was used for the West TN and national cataract surgery volume calculations.
A ministudy was performed using demographic data from 110 randomly selected patients covered by Medicare who underwent cataract surgery in 2012 by 3 different eye clinic surgeons (based on 95% confidence limits and a 10% CI for a population of 1598, a sample of 91 was needed). All patient demographic information was compliant with the Health Insurance Portability and Accountability Act of 1996, patient identifiers were not recorded, and only the compiled results were used in this article. These data were used to determine what percentages of patients needed cataract surgery on both eyes vs on one eye.
The number of eligible patients who could undergo ISCS in West TN and nationally was estimated using each group’s cataract surgery numbers and adjusting for the number of patients in whom both eyes were ready for surgery. This number was adjusted to exclude the estimated percentage of complex cataract surgical procedures. Seventy-five percent of patients eligible for ISCS were predicted to elect to proceed with ISCS vs DSCS.
Medicare payer costs per individual patient and total costs were calculated and summarized. The payer costs exclude the 20% patient coinsurance portion and patients were assumed to have met their deductible ($140.00 in 2012) from the preoperative office visit. The West TN payer costs used only ASCs in the facility portion, while the total national payer cost included a mix of 50% ASC and 50% HOPD surgical costs to mimic the estimated facility case mix in the United States.
Patients’ direct costs for anesthesia, physician, and surgical facility fees for West TN and nationally were based on the Medicare patient coinsurance rate of 20%, and no secondary insurance payments were used in this assessment. Patients were assumed to have met their deductible from the preoperative office visit. Individual patient costs and total costs were calculated using the cataract surgery volume estimates for West TN and nationally.
Patient travel distance was estimated. The postoperative and operative visit schedules used for ISCS and DSCS (for non-comanaged and comanaged patients) are shown in the eFigure in the Supplement. The same set of demographic data used to determine patient eligibility for bilateral cataract surgery was used to estimate the percentages of non-comanaged and comanaged patients, as well as the mean round-trip travel distance for non-comanaged patients (to the eye clinic) and for comanaged patients (to their optometrist’s office). The driving distances were calculated from the office address of the eye clinic or the optometrist’s office to the patient’s residence using MapQuest (http://www.mapquest.com). Because the ASC and eye clinic are located within 4½ miles of each other, the driving distance for the operative visits used the eye clinic address. The Internal Revenue Service 2012 standard mileage reimbursement rate for medical purposes of $0.23 per mile was used.22 The patient operative and postoperative visits for ISCS and DSCS were obtained from the eFigure in the Supplement and were adjusted for the non-comanaged and comanaged percentages.
The lost time from work for patients or family members was calculated only for the operative days (1 day for ISCS and 2 days for DSCS) using the 2011 West TN mean hourly wage rate ($17.22) and the 2011 national mean hourly wage rate ($23.23) for an 8-hour workday.23,24 The West TN and national individual patient costs (direct medical, travel, and lost wages) were then calculated.
A Medicare-based societal perspective was calculated. Combined were the national payer cost and the national patient cost differences between ISCS and DSCS for the estimated total Medicare cataract surgical procedures performed in a year.
All statistical analyses were performed using available software (Excel 2007; Microsoft Corporation). A sensitivity analysis was performed showing different levels of patient selection of ISCS at the 25%, 50%, and 75% levels. The sensitivity analysis showed the national Medicare surgical facility costs associated with 100% ASCs, 100% HOPDs, and a mix of 50% ASC and 50% HOPD. The sensitivity analysis of patient costs used a minimum and maximum cost format.
The West TN and national surgeon and facility fees are listed in Table 1. The costs of anesthesia care were based on the Medicare anesthesia reimbursement formula, a combination of 4 base units and additional 15-minute time units per case and are also listed in Table 1. The duration used for the mean cataract surgical procedure was 20 minutes (15 minutes of actual surgical time and 5 minutes of patient preparation time).
The West TN cataract surgery population totaled 1598, and the national cataract surgery estimate was 2 405 000 (eTable 1 in the Supplement). This estimation was based on ASC and HOPD data obtained from the 2006 study21 of ambulatory surgery in the United States, with the non–Medicare payer cataract surgical procedures among individuals 65 years or older offsetting the Medicare payer cataract surgical procedures among individuals younger than 65 years.
The demographic study demonstrated that 70.9% of patients had both eyes ready for surgery (eTable 2 in the Supplement). Reasons for having surgery performed on only one eye were that the second-eye cataract was not ready for surgery or that the patient had already had first-eye cataract surgery performed.
The number of eligible patients for ISCS is summarized in Table 2. Seventy-five percent of patients eligible for ISCS who chose ISCS were used as the base case for the West TN and national models. Table 2 also summarizes the sensitivity analysis of 25% and 50% of eligible patients who chose ISCS.
The West TN and national Medicare cost reductions per patient used bilateral cataract surgery data for ISCS and DSCS so that an accurate Medicare cost per patient comparison could be made, and these results are summarized in Table 3. The total national Medicare cost reduction of ISCS over DSCS at the 75%, 50%, and 25% eligibility levels is summarized in Table 4. A mix of 50% ASC and 50% HOPD surgical facility mix was shown to approximate the current national mix of cataract surgery procedures by facility type.15 The present study found that Medicare would reduce costs by approximately $522 million a year if 75% of eligible patients choose ISCS over DSCS in the United States.
Medicare patients’ direct medical costs for anesthesia, surgeon, and facility are listed in Table 5. No secondary insurance payments were included in the direct medical cost portion because patients who have secondary insurance must still bear the cost of the insurance premiums and a significant portion of the US Medicare population does not have secondary insurance coverage.
The round-trip mean (SD) travel distances were 63.4 (35.2) miles for non-comanaged patients and 12 (13.2) miles for comanaged patients (eTable 3 in the Supplement). The large SDs in patient travel distances are not unexpected because of the rural nature of the counties for which the eye clinic and the ASC provide care. The mean patient travel costs in West TN for surgical and postoperative visits for ISCS and DSCS were calculated and adjusted for the comanagement (31%) and non-comanagement (69%) mix, resulting in ISCS costing $50.99 and DSCS costing $91.06 (eTable 3 in the Supplement). The West TN ISCS travel cost reduction was $40.07, and the sensitivity analysis showed a range of $62.05 (+1 SD) to $18.10 (−1 SD) (eTable 4 and eTable 5 in the Supplement). Because no national travel distance data were available for cataract surgery, the West TN patient travel cost data were used for the national patient travel costs.
Lost wages were calculated using only the lost time for the actual surgical days (1 day for ISCS and 2 days for DSCS) (Table 5). The sensitivity analysis of lost labor and leisure costs using all operative and postoperative visits for patients at the West TN rate resulted in ISCS costing $551.04 and DSCS costing $964.32, for a difference of $413.28 (eSensitivity Analysis 1 in the Supplement). The West TN minimum and maximum sensitivity analysis of total individual patient cost reductions with ISCS ranged from $329.42 to $648.89 (eSensitivity Analysis 2 in the Supplement).
The total West TN and national individual patient cost reductions are listed in Table 5. The total estimated national patient cost reduction with ISCS was $261 559 894 (using a mix of 50% ASC and 50% HOPD).
The total national Medicare societal cost reductions were calculated to be approximately $783 million with a switch to ISCS. The payer portion was $522 156 426, and the patient portion was $261 559 894.
Previous studies1,6- 12 have demonstrated that ISCS is equally safe and efficacious compared with DSCS. This US-based cost-minimization analysis found that ISCS resulted in significant cost reductions compared with DSCS from the payer and patient perspectives. Using ISCS compared with DSCS, Medicare would reduce costs by approximately $522 million per year, and patients would reduce costs (direct medical, travel, and lost wages) by approximately $261 million per year.
The use of regional data to form a model had several weaknesses. The major weakness was a generalizability risk in attempting to apply this regional model on a national basis. Some of this risk was reduced by using Medicare payment data, which should theoretically adjust for the differences in regional costs because Medicare factors this into the regional payment schedules.
This study had many limitations. One limitation was the small sample size used to obtain the demographic data. Another limitation was using Medicare as the sole payer because this did not account for private insurance and for Medicaid cataract surgery payments. Previous studies15,16 support using Medicare as the representative payer by confirming that it was the primary payer in more than 80% of cataract surgical procedures in the United States. A significant advantage to using Medicare was that national mean and local reimbursement schedules are readily obtainable, unlike fee schedules for many private insurers. Medicare payment policy also significantly affects the entire US health care system because many private insurers tie their payment schedules to a percentage of Medicare. Most important, this study accounted for only 80% of total US cataract surgery expenditures because the non-Medicare market was not evaluated.
This model was limited by the fact that inputs may vary geographically or based on physician practice patterns. The modeling costs are sensitive to the underlying assumptions affecting the number of patients potentially eligible for ISCS such as the total number of cataract surgical procedures, the percentage of patients in whom both eyes are ready for surgery, the percentage of complex cataract surgical procedures, and the percentage of patients who will choose to have ISCS. The 75% of eligible patients choosing ISCS represented a 48.2% ISCS rate of total cataract surgery cases. Early evidence indicates that adoption rates may be high because some hospitals in Finland are approaching having 50% of all cataract surgical cases performed as ISCS.3
Patient travel and lost wage estimates are limited by several difficulties. These include estimating how many days of lost wages to count, whether the person driving the patient to surgery and postoperative visits was employed, what wage rate to use, and where geographic variations exist in travel distance and comanagement rates.
International comparisons will be difficult without significant adjustments. However, the results herein should be transferable to different regions within the US health care system because Medicare payments are adjusted for regional cost differences.
The results of this study are similar to those of previous international cost analyses comparing ISCS with DSCS. A randomized, prospective clinical trial12 in Finland using a societal perspective evaluated medical costs, nonmedical costs, and time costs between ISCS and DSCS, with ISCS resulting in savings of €449 per patient in medical costs, €739 per patient when travel and paid home care costs were included, and €849 per patient when lost work time was included. A Swedish study13 examined ISCS and DSCS by comparing hospital resource use and value to patients and found that DSCS was 14% more expensive than ISCS. These 2 international cost analyses12,13 and a third Canadian study14 found that ISCS was more efficient from a cost standpoint.
As health care costs continue to rise in the United States, policy makers are examining ways to increase efficiency in the provision of care, while reducing costs. Medicare will bear a significant portion of this increased health care spending due to the fact that the baby boomer generation started becoming eligible for Medicare coverage in 2011, as well as a result of persons living longer.25,26 In 2011, Medicare covered 48.7 million individuals,27 and the age group 65 years or older is predicted by 2020 to increase by 53%.26 By 2050, the population 65 years or older is estimated to grow to 88.5 million.28 Medicare’s costs are expected to grow from 3.7% of the gross domestic product in 2011 to between 6% and 7% of the gross domestic product in 2040 based on recent data.27 The projected increase in cataract surgery volume will have a substantial effect on Medicare’s finances, and Medicare would benefit from paying less per patient for cataract surgery with a switch from DSCS to ISCS. Many private insurance payers are likely to follow Medicare’s lead and to set policies accordingly.
With ISCS, patients and their families would benefit from lower direct medical costs and from fewer surgical and postoperative visits. The aging of the US population will mean more medically related trips and most likely increasing productivity losses for patients and their families, but switching to ISCS has the potential to offset some of these losses.
A major concern is how physicians’ behavior will be influenced by cataract surgery payment rates, especially given the second-eye discounted payment with ISCS. Further studies are needed to elucidate how a change from DSCS to ISCS would affect surgeons and surgical facilities. Specifically, could cost savings and efficiency gains offset the loss of revenue that would occur after this transition? Potential policy implications should be evaluated from the physician and surgical facility perspectives.
Submitted for Publication: February 6, 2014; final revision received March 21, 2014; accepted March 27, 2014.
Corresponding Author: Sean T. Neel, MD, MSc, Eye Clinic, PC, 668 Skyline Dr, Jackson, TN 38301 (email@example.com).
Published Online: July 17, 2014. doi:10.1001/jamaophthalmol.2014.2074.
Conflict of Interest Disclosures: None reported.
Additional Information: This article is an extensively revised and rewritten portion of an unpublished master’s thesis (A Cost-Minimization and Policy Analysis Comparing Immediate Sequential Cataract Surgery and Delayed Sequential Cataract Surgery From Payer, Patient, Physician, and Surgical Facility Perspectives in the United States) completed September 2013 at the London School of Economics and Political Science, London, England, to fulfill the requirements for an MSc degree in health economics, policy, and management.