Cataract surgery and effectiveness. 2. An index approach for the measurement of output and efficiency of cataract surgery at different surgery departments

Budget impact model of Mydrane®, a new intracameral injectable used for intra-operative mydriasis, from a UK hospital perspective

BACKGROUND

During cataract surgery, maintaining an adequate degree of mydriasis throughout the entire operation is critical to allow for visualisation of the capsulorhexis and the crystalline lens. Good anaesthesia is also essential for safe intraocular surgery. Mydrane® is a new injectable intracameral solution containing two mydriatics (tropicamide 0.02% and phenylephrine 0.31%) and one anaesthetic (lidocaine 1%) that was developed as an alternative to the conventional topical pre-operative mydriatics used in cataract surgery. This study aimed to estimate the budget impact across a one year time frame using Mydrane® instead of topical dilating eye drops, for a UK hospital performing 3,000 cataract operations a year.

METHODS

A budget impact model (BIM) was developed to compare the economic outcomes associated with the use of Mydrane® versus topical drops (tropicamide 0.5% and phenylephrine 10%) in patients undergoing cataract surgery in a UK hospital. The outcomes of interest included costs and resource use (e.g. clinician time, mydriasis failures, operating room time, number of patients per vial of therapy etc.) associated with management of mydriasis in patients undergoing cataract surgery. All model inputs considered the UK hospital perspective without social or geographical variables. Deterministic sensitivity analyses were also performed to assess the model uncertainty.

RESULTS

Introduction of Mydrane® is associated with a cost saving of £6,251 over 3,000 cataract surgeries in one year. The acquisition costs of the Mydrane® (£18,000 by year vs. £3,330 for eye drops) were balanced by substantial reductions in mainly nurses' costs and time, plus a smaller contribution from savings in surgeons' costs (£20,511) and lower costs associated with auxiliary dilation (£410 due to avoidance of additional dilation methods). Results of the sensitivity analyses confirmed the robustness of the model to the variation of inputs. Except for the duration of one session of eye drop instillation and the cost of Mydrane®, Mydrane® achieved an incremental cost gain compared to tropicamide/phenylephrine eye drops.

CONCLUSIONS

Despite a higher acquisition cost of Mydrane®, the budget impact of Mydrane® on hospital budgets is neutral. Mydrane® offers a promising alternative to traditional regimes using eye drops, allowing for a better patient flow and optimisation of the surgery schedule with neutral budget impact.

The impact of cataract surgery questionnaire: re-evaluation using Rasch analysis

PURPOSE

The Impact of Cataract Surgery (ICS) questionnaire was designed to assess cataract surgery outcomes. The aim of this study was to describe the psychometric properties of the ICS questionnaire using the Rasch model in a cataract population.

METHODS

Ninety-one patients waiting to undergo cataract surgery in the first or second eye at the Flinders Medical Centre, Adelaide, South Australia self-administered the four-item ICS questionnaire. Rasch analysis was performed to assess behaviour of response categories, ability to differentiate between participants' visual abilities (person separation; minimum acceptable 2.0), if items measure a single underlying construct [i.e. unidimensionality assessed by fit statistics and further by principal components analysis (PCA)] and matching of item difficulty to participant ability (targeting; ideal < 0.5 logits). Adequate person separation was defined as basic requirement for a measure, failing which further assessment such as PCA was not performed.

RESULTS

The four-item ICS questionnaire did not meet the required measurement properties (person separation zero). Response categories did not behave as intended, requiring the collapsing of categories for one item (read ordinary newspaper-size print). One item misfit (estimating distance) indicating that it was not measuring the same construct as other items. However, person separation failed to improve following the deletion of this item. Targeting was -0.46 logits, indicating that the item difficulty was well suited to the visual abilities of the participants.

CONCLUSION

In its present form, the ICS is unsuitable for visual disability assessment in patients awaiting cataract surgery. Other, better visual function questionnaires are available and preferred.

Immediate versus delayed sequential bilateral cataract surgery: an analysis of costs and patient value

PURPOSE

To compare resource utilization of two different strategies for bilateral cataract surgery: immediate sequential cataract surgery (ISCS) versus delayed sequential cataract surgery (DSCS). The purpose was also to analyse the value for the patient of undergoing ISCS versus DSCS.

METHODS

Differences in routines and resource utilization between ISCS (n = 17) and DSCS (n = 80) were studied in a cohort of cataract surgery patients at our clinic in Karlskrona, Sweden. Costs were extracted from an earlier publication by the same clinic. The value for the patient was studied using the capability index, based on published data on the benefit to the patient of ISCS or DSCS using the Catquest questionnaire.

RESULTS

Operating both eyes of a patient was 1.14 times more expensive with DSCS than with ISCS including all surgical costs. The value to the patient of undergoing ISCS depended on the time between first- and second-eye surgery in DSCS and the remaining lifetime after both-eye surgery. A long waiting time for second-eye surgery and a short remaining lifetime decreased the patient value of DSCS compared to ISCS.

CONCLUSION

DSCS is 14% more expensive than ISCS. The value for the patient of ISCS compared to DSCS depends on how long the period will be between first- and second-eye surgery in DSCS and also on the patient's survival time after surgery.

Global Cost-effectiveness of Cataract Surgery

OBJECTIVE

To determine the cost-effectiveness of cataract surgery worldwide and to compare it with the cost-effectiveness of comparable medical interventions.

DESIGN

Meta-analysis.

PARTICIPANTS

Approximately 12,000 eyes in the studies selected.

METHODS

Articles were identified by searching the literature using the phrase cataract surgery, in combination with the terms cost, cost-effectiveness, and cost-utility. Terms used for the comparable medical interventions search included epileptic surgery, hip arthroplasty, knee arthroplasty, carpal tunnel surgery, and defibrillator implantation. The search was restricted to the years 1995 through 2006. Cataract surgery costs were converted to 2004 United States dollars (US$). Cost-utility was calculated using: (1) costs discounted at 3% for 12 years with a discounted quality-adjusted life years (QALY) gain of 1.25 years, and (2) costs discounted at 3% for 5 years with a discounted QALY gain of 0.143 years. The Cataract Surgery Affordability Index (CSAI) for each country was calculated by dividing the cost of cataract surgery by the gross national income per capita for the year 2004.

MAIN OUTCOME MEASURES

Cost-utility in 2004 US$/QALY and affordability of cataract surgery relative to the United States.

RESULTS

Cost-utility values for cataract surgery (first eye) varied from $245 to $22,000/QALY in Western countries and from $9 to $1600 in developing countries. In developed countries, the cost-effectiveness of cataract surgery estimated by Choosing Interventions That Are Cost Effective ranged from, in international dollars (I$), I$730 to I$2400/disability-adjusted life years (DALY) averted, and I$90 to I$370/DALY averted in developing countries. The CSAI varied from 17% to 189% in developed countries and 29% to 133% in developing countries compared with the United States. The cost-utility of other comparable medical interventions was: epileptic surgery, $4000 to $20,000/QALY; hip arthroplasty, $2300 to $4800/QALY; knee arthroplasty, $6500 to $12,700/QALY; carpal tunnel surgery, $140 to $280/QALY; and defibrillator implantation, $700 to $23,000/QALY.

CONCLUSIONS

The cost-utility of cataract surgery varies substantially, depending how the benefit is assessed and on the duration of the assumed benefit. Cataract surgery is comparable in terms of cost-effectiveness to hip arthroplasty, is generally more cost-effective than either knee arthroplasty or defibrillator implantation, and is cost-effective when considered in absolute terms. The operation is considerably cheaper in Europe and Canada compared with the United States and is affordable in many developing countries, particularly India.

The Swedish National Cataract Register: A 9-year review

The Swedish National Cataract Register (NCR) has been collecting data on cataract extractions in Sweden since 1992. This unique national database now contains data pertaining to more than 400 000 operations, representing 93.4% of all operations performed nationwide during 1992-2000. Clinic participation in the NCR is voluntary. Tests have shown NCR data to be extremely reliable, while the participation of nearly all providers of cataract surgery in Sweden makes the data highly representative of cataract surgery throughout the country. The NCR collects pre- and per-operative data for every cataract extraction performed at participating clinics. Surgical outcome data and data about patients' self-assessed visual function is collected in approximately 10% of cases. Since 1998, all cases of suspected postoperative endophthalmitis have also been reported to the NCR. The rate of surgery has increased from 4.47 to 7.26 per 1000 inhabitants during the period. Female subjects have constituted about 66% of all operated subjects each year and the mean age of patients has slowly increased from 75.2 to 76.1 years. Average pre-operative visual acuity has improved each year. Second eye surgery has increased from 28.5% to 36.8% of all surgeries. Phacoemulsification has reached 98% as type of surgery (in 2000) and 92.7% of all intraocular lenses are foldable. Surgical outcome has improved by achieving a final refraction closer to the target refraction and less surgically induced astigmatism. The positive impact of cataract surgery in very elderly people has been demonstrated, as has the positive effect of second eye surgery, especially in young subjects. The NCR has served to enhance knowledge about trends and results of cataract surgery in Sweden. This review article describes some of the activities carried out and their results.