Report Title: Healthcare Performance Measurement & Reporting for LASIK surgery services provided by OPTIMAX Malaysia

Transcription

1 Page 1 of 22 Report Title: Reporting for LASIK surgery services provided by OPTIMAX Malaysia Protocol number: HR Document type: Healthcare Performance Report Document status: FINAL Release Date: 19 May 2011 Number of pages: 22 Client Investigators Site Coordinator Consultant Statisticians Data management & audit Optimax Eye Specialist Centre Stephen Chung SH MS.Ophth Chuah KL FRCOphth NorAzlina BN MS.Ophth Yen SS MS.Ophth Lim Yee Yin Daniel Jones Lim T.O. FRCP, M.Stat Hoo LP PhD, Lena Yeap MSc Teo JS MSc 1

2 Page 2 of 22 Contents More analysis Summary Introduction Analysis set Outcomes of LASIK surgery Performance measurement for LASIK surgery & Risk adjustment model Performance measures for LASIK surgery Risk adjustment Risk adjusted Performance results Conclusion Appendix Glossary List of Abbreviations Tables and Figures Table 1: Reason for ineligibility... 6 Table 2a: Reason for exclusion from efficacy analysis set... 7 Table 2b: Reason for exclusion from safety analysis set... 7 Table 3: Baseline characteristics of patients undergoing LASIK surgery... 7 Table 4A: Visual Outcomes of LASIK surgery at 6-month post-op... 9 Table 4B: Refractive Outcomes of LASIK surgery at 6-month post-op... 9 Table 4C: Safety Outcomes of LASIK surgery Table 5: Outcomes of LASIK surgery by individual surgeons Figure 1a: Comparative performance of Risk adjusted Visual acuity outcome of LASIK surgery among 4 surgeons Figure 1b: Comparative performance of Risk adjusted Visual acuity outcome of LASIK surgery among 4 surgeons Table 6a: Comparative quarterly performance of Risk adjusted Visual acuity outcome of LASIK surgery among 4 surgeons Figure 6a: Comparative quarterly performance of Risk adjusted Visual acuity outcome of LASIK surgery (Uncorrected visual acuity (UCVA) >=6/7.5 at 6 months post-op ) Table 6b: Comparative quarterly performance of Risk adjusted Visual acuity outcome of LASIK surgery among 4 surgeons Figure 6b: Comparative quarterly performance of Risk adjusted Visual acuity outcome of LASIK surgery (Uncorrected visual acuity (UCVA) >=6/12 at 6 months post-op ) Table 7: Performance measures for LASIK surgery Table 8a: Relationship between Visual outcome of LASIK surgery (Uncorrected visual acuity (UCVA) >=6/7.5 at 6 months post-op) and various putative prognostic factors Table 8b: Relationship between Visual outcome of LASIK surgery (Uncorrected visual acuity (UCVA) >=6/12 at 6 months post-op) and various putative prognostic factors

3 Page 3 of 22 Summary Introduction We measure the performance of LASIK surgery services provided by Optimax Eye Specialist Centre. The surgical service was provided by 4 surgeons at its TTDI branch. Three performance measures were selected: 1. Post-operative Uncorrected visual acuity. This is the acuteness or clearness of vision as measured using standard vision chart that is achieved after surgery. This is a measure of visual outcome, a standard measure of treatment effectiveness. 2. Post-operative refraction within +0.5 Diopters of target refraction. This measures the precision of the refractive correction, a standard measure of refractive outcome of LASIK surgery 3. Worsening of visual acuity. While the intended effect of LASIK surgery is to improve the patient s visual acuity by correcting the refractive error, complications or other unintended effects of surgery could result in worsening of visual acuity. This is therefore an important measure of patient safety Data & Model For purpose of performance measurement, data were available from 932 patients who have had 1620 LASIK surgical procedures among them (most patients have had surgery for both eyes) for correction of myopia between January and December For efficacy analysis, data from 287 procedures on 167 patients were excluded from analysis for the following reasons: Without post-op visual acuity data at all (57 procedures) Without post-op visual acuity data at 1 week post op for INTRALASIK, LASIK and LASIK-XP surgeries (33 procedures) Without post-op visual acuity data at 3-month post op for LASEK and Epi-LASIK surgeries (195 procedures) Too few procedures performed by single doctor (2 procedures) For safety analysis, data from a further 7 procedures were excluded for lack of BCVA data. Performance results were risk adjusted using a statistical model that included 4 patients factors that affect the visual outcome of surgery. These are age, sex, degree of myopia and astigmatism. Results All surgeons achieved excellent results in 2010: The mean success rate (defined as UCVA at 6-month post-op 6/7.5 or better) among the 4 surgeons was 95%, and 99% for UCVA 6/12 or better. Their risk adjusted success rate varies from 93% to 97% ; all 95% confidence intervals overlap 100% success rate. For UCVA 6/12 or better, all surgeons uniformly achieved 99% risk adjusted success rate. Their success rates were also consistent, without significant variation in outcomes from quarter to quarter throughout the year The overall on-target refractive error correction rate (defined as MRSE at 6 months within + 0.5D of Target=0) was 91%; for correction of spherical error alone, the on-target rate was higher at 95%. 3

4 Page 4 of 22 The result of patient safety outcome was also reassuring. No patient has suffered serious loss of visual acuity as a result of LASIK surgery at 6 months post-op. All patients had best spectacle corrected visual acuity (BCVA) better than 6/12 at 6 months post-op. Caution is however warranted in interpreting the performance results reported here. The analysis was based entirely on retrospective data collected for administrative purpose rather than specifically for performance measurement. Not surprisingly, there was substantial data error and extensive data cleaning efforts were required prior to analysis. Several known prognostic factors (corneal curvature, corneal thickness, pupil size etc) could be included in the statistical model for risk adjustment. The risk model will require further development and validation, pending improvement in data quality and availability of data on known prognostic factors Both the above issues are being addressed at the prospective phase of this initiative (started since January 2011) where data required will be defined clearly and data will be collected prospectively using systematic data reporting mechanisms and subject to ongoing data QC to assure data quality. Conclusion The performance of LASIK surgery services as provided by the Optimax eye care group is reassuring. These results also established a sound scientific basis and operational experience for the Optimax eye healthcare group to embark on routine prospective measurement of the performance LASIK surgery services. This has been initiated since January

5 Page 5 of Introduction Laser-Assisted In-Situ Keratomileusis or LASIK in short, is a surgical technique for the correction of myopia, hyperopia and astigmatism. It involves the use of excimer laser to ablate corneal tissue thus reshaping in order to correct the refractive error. LASIK [1,2] has evolved from a variety of techniques including lamellar keratoplasty, photorefractive keratectomy, and since the 1990s has been widely used. The technology associated with the LASIK procedure has also advanced rapidly since then. Recent innovations include new femtolaser microkeratome, newer laser technology (Faster laser speed, finer laser spots, eyetracking system etc), wavefront and topographic custom ablation. Numerous prospective randomized controlled trials and meta-analyses of these trials have demonstrated the safety and efficacy of LASIK for the correction of refractive errors [3-11]. Refractive surgery was first introduced into Malaysia by Optimax in Since then its use has increased rapidly with the vast majority of the procedures still being performed by Optimax. Optimax has also grown from a single centre with a lone surgeon to become the leading provider of LASIK and other specialist eye care services in Malaysia with a network of 12 centers and 9 ophthalmologists. Worldwide there is an increasing interest in measuring the performance of healthcare providers [12,13,14]. The publication of the highly influential report, Performance Measurement: Accelerating Improvement, by the Institute of Medicine in 2006 [15], has added greater impetus for performance measurement as a central tenet of health care reform. Our government has also recently introduced KPI to measure the performance of government services as part of the Government Transformation Programme [16]. However, this has yet to impact on the public health services where performance measurement and reporting activity remains undeveloped. Similarly in the private healthcare sector, while financial performance measures are well established and routinely reported, robust healthcare performance measures that reflect the core business of the healthcare industry are practically non-existent. As a testament to Optimax s leadership position in the field of LASIK surgery services in Malaysia, Optimax has agreed to subject its LASIK services to performance measurement and reporting by an independent third party. This is intended not just to support quality improvements initiatives within Optimax, but also as a reflection of Optimax s commitment to a high standard of accountability in healthcare. To this end, measuring and reporting the performance of Optimax s LASIK surgery services is intended to assure healthcare payers (insurance companies, employers) that they are getting value for their money, to respond to the requirements of quality certification/ accreditation organizations (ISO9000, JCI) and regulators (CKAP MOH), and most importantly to aid customers, both patients as well as health professionals who refer patients, in making informed choices. This is the first in a series of reports on the performance LASIK surgery by Optimax. 5

6 Page 6 of Analysis set Between Jan and December 2010 inclusive, data were available from 953 patients who have had 1760 LASIK surgical procedures (most patients have had surgery for both eyes) for correction of myopia performed by 5 surgeons at Optimax s TTDI centre. Of these, only 932 patients who have had 1620 procedures were eligible for inclusion in this analysis for the purpose of performance measurement. Efficacy analysis set For efficacy analysis (visual and refractive outcomes), a further 167 patients who have had 287 procedures were excluded from analysis for missing efficacy measure data as follows: Without post-op visual acuity data at all (57 procedures) Without post-op visual acuity data at 1 week post op for INTRALASIK, LASIK and LASIK-XP surgeries (33 procedures) Without post-op visual acuity data at 3-month post op for LASEK and Epi-LASIK surgeries (195 procedures) Safety analysis set For safety analysis (BCVA outcome), data from 7 procedures were excluded because of missing BCVA data (These 7 procedures were from 5 patients, but only 2 patients completely excluded as data for procedures on both eyes were missing) LASIK surgery on 1760 eyes for 953 patients Eligible for analysis 1620 eyes from 932 patients Ineligible 140 eyes, 21 patients Refer table below for details Efficacy analysis set 1333 eyes from 765 patients Excluded from Efficacy analysis set 287 eyes, 167 patients Refer table below for details Safety analysis set 1326 eyes from 763 patients Excluded from Safety analysis set 7 eyes, 2 patients Refer table below for details Table 1: Reason for ineligibility Reason Procedure % Patient % Both eyes were treated for hypermetropia Sole eye treated for monovision Sole eye treated for hypermetropia One of two eyes treated for hypermetropia or monovision

7 Page 7 of 22 Table 2a: Reason for exclusion from efficacy analysis set Reason Procedure % Patient % No post-op UCVA All week post op for INTRALASIK, LASIK and LASIK-XP 3-month post op for LASEK and Epi LASIK Too few procedures by a doctor Table 2b: Reason for exclusion from safety analysis set Reason Procedure % Patient % No post-op BCVA at all Baseline descriptive analysis The table below summarizes the patients characteristics and LASIK surgery for the 765 patients included in this analysis. Table 3: Baseline characteristics of patients undergoing LASIK surgery Patient characteristics Statistics Number of patients=765 Mean (SD) Age, years (7.12) Sex, No. (%) Male 263 (34.38) Female 502 (65.62) Number of procedures=1333 Prior Refractive surgery, No. (%) No data Type of LASIK, No. (%) INTRALASIK 1183 (88.75) LASIK 44 (3.3) LASIK XP 35 (2.63) EPILASIK 65 (4.88) LASEK 6 (0.45) Pre-Op Visual Acuity(VA) No. (%) with manifest Best spectacle Corrected VA (BCVA) >= 1302 (97.67) 6/6 No. (%) with manifest BCVA >= 6/ (100) Mean (SD) manifest BC VA (decimal scale) (0.0405) Mean (SD) manifest BCVA (LogMAR scale) (0.0183) No. (%) with cycloplegic BCVA >= 6/ (95.95) No. (%) with cycloplegic BCVA >= 6/ (100) Mean (SD) cyclo BCVA (decimal scale) (0.0489) Mean (SD) cyclo BCVA (LogMAR scale) (0.0231) 7

8 Page 8 of 22 Pre-Op Refractive measurements Spherical Error (SER), Dioptre (D) Mean (SD) Manifest Spherical Error (2.2) Range(max, min) Manifest Spherical Error (-0.25, -12.5) Mean (SD) Cycloplegic Spherical Error (2.21) Range(max, min) Cycloplegic Spherical Error (-0.25, -12) No. (%) with Manifest Spherical Error >=(neg) -6.0 D (Low to 954 (71.57) moderate Myopia) No. (%) with Manifest Spherical Error < -6.0 D (Moderate to 379 (28.43) High Myopia) No. (%) with Cycloplegic Spherical Error >=(neg) -6.0 D 982 (73.67) No. (%) with Cycloplegic Spherical Error < (neg)-6.0 D 351 (26.33) Cylindrical Error (CER), Dioptre (D) Mean (SD) Manifest Cylindrical Error (0.81) Range (max, min) Manifest Cylindrical Error (0, -5.5) Mean (SD) Cycloplegic Cylindrical Error (0.82) Range (max, min) Cycloplegic Cylindrical Error (0.25, -5.75) No. (%) with Manifest Cylindrical Error >= (neg)-2.0 D (Low to 1220 (91.52) moderate Astigmatism) No. (%) with Manifest Cylindrical Error < (neg)-2.0 D (Moderate 113 (8.48) to High Astigmatism) No. (%) with Cycloplegic Cylindrical Error >= (neg)-2.0 D 1220 (91.52) No. (%) with Cycloplegic Cylindrical Error < (neg)- 2.0D 113 (8.48) Spherical Equivalent (SEQ) [SEQ=SER CER], Dioptre (D) Mean (SD) Manifest Spherical Equivalent (2.26) Range(max, min) Manifest Spherical Equivalent (-0.62, ) Mean (SD) Cycloplegic Spherical Equivalent (2.26) Range(max, min) Cycloplegic Spherical Equivalent (-0.5, ) Other Pre-Op/ Intra-op Ophthalmic measurements Mean (SD) Corneal Curvature (Keratometry) Flat K (1.34) Mean (SD) Corneal Curvature (Keratometry) Steep K (1.46) Mean (SD) Corneal Curvature (Keratometry) Average k Average k = (Flat K+Steep K)/2 Flap thickness (Pachymetry), mm Pupil size, mm (1.35) No data No data Refer Appendix for results on Baseline characteristics of patients who had required enhanced LASIK surgical procedures 8

9 Page 9 of Outcomes of LASIK surgery The table below summarizes the outcomes (visual acuity, refractive and safety) of LASIK treatment for all procedures included in this analysis. Table 4A: Visual Outcomes of LASIK surgery at 6-month post-op Visual Outcome Statistics 6-month post-op, N= 1333 UCVA (Fractional scale) Median 6/6 IQR (6/6, 6/6) Min, Max (6/45, 6/4.5) UCVA (Decimal scale) Mean 0.96 SD 0.12 UCVA (LogMAR scale) Mean 0.02 SD 0.07 UCVA 6/7.5 or better No (%) (94.67) UCVA 6/12 or better No (%) (98.95) Table 4B: Refractive Outcomes of LASIK surgery at 6-month post-op Refractive Outcome Statistics 6-month post-op N= 1333 Manifest Refractive Spherical Equivalent (MRSE) Mean (SD) (0.3) Min, Max (-1.5, 1.75) MRSE within + 0.5D of Target=0 No. (%) 1213 (91) MRSE < - 0.5D of Target=0 No. (%) 102 (8) MRSE > + 0.5D of Target=0 No. (%) 18 (1) Change in Post-op MRSE from Baseline MRSE Mean (SD) 5.19 (2.3) Min, Max (0.5, 12.75) Manifest Spherical Error (MSPH) Mean (SD) (0.33) Min, Max (-1.5, 2) MSPH within + 0.5D of Target=0 No. (%) 1260 (95) MSPH < - 0.5D of Target=0 No. (%) 36 (3) MSPH > + 0.5D of Target =0 ie Over-Correction No. (%) 37 (3) Change in Post-op MSPH from Baseline MSPH Mean (SD) 4.83 (2.27) Min, Max (0, 13) Manifest Cylindrical Error (MCYL) Mean (SD) (0.25) Min, Max (-2.5, 0) MCYL within + 0.5D of Target=0 No. (%) 1233 (93) MCYL < - 0.5D of Target=0 No. (%) 100 (8) MCYL > + 0.5D of Target =0 No. (%) 0 (0) Change in Post-op MCYL from Baseline MCYL Mean (SD) 0.64 (0.78) Min, Max (-0.75, 4.75) 9

10 Page 10 of 22 Table 4C: Safety Outcomes of LASIK surgery Safety Outcome Statistics 6-month post-op, N= 1326 Loss of >= 2 lines of BCVA No. 0 (%) (0) Final BCVA equal or worst than 6/12 No. 0 (%) (0) Table 5: Outcomes of LASIK surgery by individual surgeons Surgeons A B C D N Outcome measures Visual outcome No (%) with UCVA 6/7.5 or better at 3 months 370(97.11) 95(96.94) 727(92.85) 67(94.37) No (%) with UCVA 6/12 or better at 3 months 379(99.48) 96(97.96) 775(98.98) 70(98.59) No (%) with UCVA 6/7.5 or better at 6 months 371(97.38) 95(96.94) 730(93.23) 66(92.96) No (%) with UCVA 6/12 or better at 6 months 377(98.95) 97(98.98) 775(98.98) 70(98.59) Refractive outcome No (%) with MRSE at 3 months within + 0.5D of Target=0 No (%) with MRSE at 6 months within + 0.5D of Targe=0 Safety outcome No (%) with Loss of >= 2 lines BSCVA at 3 months No (%) with Final BSCVA at 3 months worse than 6/12 No (%) with Loss of >= 2 lines BSCVA at 6 months No (%) with Final BSCVA at 6 months worse than 6/12 355(93.18) 86(87.76) 697(89.02) 64(90.14) 356(93.44) 87(88.78) 704(89.91) 66(92.96) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 10

11 Page 11 of Performance measurement for LASIK surgery & Risk adjustment model 5.1 Performance measures for LASIK surgery In healthcare, performance measures are those process, structure, efficiency, or outcome measures that have been developed using rigorous methodology. These measures are intended not only for clinical quality improvement but they have attributes rendering them suitable for public reporting, explicit comparisons of care between healthcare providers, accreditation, pay for performance programs, or other forms of accountability. For LASIK surgery, we selected three performance measures: 1. Post-operative Uncorrected visual acuity. This is the acuteness or clearness of vision as measured using standard vision chart that is achieved after surgery. This is a measure of visual outcome, a standard measure of treatment effectiveness. 2. Post-operative refraction within +0.5 Diopters of target refraction. This measures the precision of the refractive correction, a standard measure of refractive outcome of LASIK surgery 3. Worsening of visual acuity. While the intended effect of LASIK surgery is to improve the patient s visual acuity by correcting the refractive error, complications or other unintended effects of surgery could result in worsening of visual acuity. This is therefore an important measure of patient safety Details on the selected performance measures are described in the Appendix 5.2 Risk adjustment Valid measurement of performance also requires statistical methods that account for differences in patient characteristics (between providers and over time) as well as random variation arising from small sample size or infrequent outcome event of interest. In other words, performance results need to be so called risk-adjusted to eliminate the influence of those elements of the patient population that affect results but are out of the control of the healthcare providers whose performance are being assessed. We were unable to identify an established statistical model for the purpose of risk adjustment. Based on a literature review, we consider the following known prognostic factors for inclusion in the model development. However, not all factors could be included for reasons given below too: # Risk factors Inclusion in risk model. If not, reason for exclusion 1. Age Included 2. Sex Included 3. Prior refractive surgery No data 4. Pupil size No data 5. Spherical errors or degree of myopia Included 6. Cylindrical errors or degree of astigmatism Included 7. Corneal thickness No data 8. Corneal topography (Steep and Flat K) Included 9. Intra-ocular pressure No data 10. Laser transition zone No data 11. Types of LASIK surgery Some types of surgery have too few records, hence excluded For the purpose of risk modeling, we define successful visual outcome is defined as LASIK surgery that results in a patient attaining uncorrected visual acuity (UCVA) of 6/7.5 or better 11

12 Version No: 3.4 Page 12 of 22 at 6 months post-op. This is justified by the marked variability in the relationship between measure of refractive error (eg spherical error) and UCVA which can be subjective. The scatter plot from the data below illustrates this: Lowess smoother MRSE 6 mths post-op bandwidth =.8 Our model building results were as follows: Age appears to have an effect with the youngest and oldest age groups less likely to have successful visual outcomes but these did not reach statistical significance. Female patients have poorer UCVA results. Subsequent investigation showed that this ws entirely due to systematic bias in measuring females UCVA. For a given refractive error, female reported worst UCVA than male. The degree of myopia and astigmatism were clearly highly influential, the more severe the myopia or astigmatism, the worst the outcome, as is well reported in the literature too. Corneal curvature is expected to be influential. However, patients with high or low corneal curvature were systematically excluded from treatment by the treating physicians according to current practice standard. Hence, the range of values found among the treated patients were too restricted (mean k 43.8, SD 1.35, min and max. 47.9) to elicit an effect on outcome. Based on the above findings, the final model to be used for risk adjustment includes only age, sex, degree of myopia and astigmatism. This will require refinement as more data on more prognostic factors as well as for more patients become available in future. Details on the risk modelling are shown in the Appendix 12

13 D C Surgeon B A D C Surgeon B A Version No: 3.4 Page 13 of Risk adjusted Performance results We use the risk model developed above to adjust the visual acuity outcome results for the 4 surgeons (anonymized as A, B, C and D) included in this analysis. Results are shown in the figures below Figure 1a: Comparative performance of Risk adjusted Visual acuity outcome of LASIK surgery among 4 surgeons Values are Percent of patients with UCVA >=6/7.5 at 6 months post-op (95% confidence interval) Risk adjusted Visual Acuity outcome (%) 95% CI A (87.51, 100) B (77.24, 100) C (86.50, 100) D (70.27, 100) All (lower 95% CI, Upper 95% CI) Adjusted success rate Figure 1b: Comparative performance of Risk adjusted Visual acuity outcome of LASIK surgery among 4 surgeons Values are Percent of patients with UCVA >=6/12 at 6 months post-op (95% confidence interval) Surgeons Surgeons Risk adjusted Visual Acuity outcome (%) 95% CI A (79.30, 100) B (92.00, 100) C (88.96, 100) D (75.57, 100) All (lower 95% CI, Upper 95% CI) Adjusted success rate 13

14 Adjusted success rate Version No: 3.4 Page 14 of 22 Table 6a: Comparative quarterly performance of Risk adjusted Visual acuity outcome of LASIK surgery among 4 surgeons. Values are Percent of patients with Uncorrected visual acuity (UCVA) >=6/7.5 at 6 months post-op (95% confidence interval) Surgeon Q1 Q2 Q3 Q4 Overall A 100% 100% 97.12% 98.84% 97.42% (82.04, 100) (82.44, 100) (72.74, 100) (79.75, 100) (87.51, 100) B 99.96% 93.62% 97.79% 100% 96.68% (72.25, 100) (42.73, 100) (54.93, 100) (44.9, 100) (77.24, 100) C 91.25% 92.29% 92.75% 90.79% 93.27% (76.74, 100) (78.99, 100) (80.49, 100) (77.26, 100) (86.5, 100) D 93.51% 89.71% 90.22% 88.98% 92.62% (54.43, 100) (52.22, 100) (41.18, 100) (30.84, 100) (70.27, 100) Figure 6a: Comparative quarterly performance of Risk adjusted Visual acuity outcome of LASIK surgery (Uncorrected visual acuity (UCVA) >=6/7.5 at 6 months post-op ) Quaterly Performance of Doctor A (lower 95% CI, Upper 95% CI) Quaterly Performance of Doctor B (lower 95% CI, Upper 95% CI) Q1 Q2 Q3 Q4 Period Q1 Q2 Q3 Q4 Period Adjusted success rate Quaterly Performance of Doctor C (lower 95% CI, Upper 95% CI) Quaterly Performance of Doctor D (lower 95% CI, Upper 95% CI) Q1 Q2 Q3 Q4 Period Q1 Q2 Q3 Q4 Period 14

15 Adjusted success rate Adjusted success rate Version No: 3.4 Page 15 of 22 Table 6b: Comparative quarterly performance of Risk adjusted Visual acuity outcome of LASIK surgery among 4 surgeons. Values are Percent of patients with Uncorrected visual acuity (UCVA) >=6/12 at 6 months post-op (95% confidence interval) Surgeon Q1 Q2 Q3 Q4 Overall A 99.95% 99.92% 95.43% 100% 99% (72.52, 100) (47.58, 100) (53.6, 100) (43.59, 100) (79.3, 100) B 99.48% 98.57% 99.51% 98.38% 98.97% (84.26, 100) (84.73, 100) (86.7, 100) (84.16, 100) (92, 100) C 99% 99.06% 97.10% 99.93% 98.95% (79.88, 100) (80.02, 100) (73.12, 100) (81, 100) (88.96, 100) D 99.81% 99.70% 99.49% 89.98% 98.68% (59.02, 100) (59.81, 100) (47.37, 100) (31.19, 100) (75.57, 100) Figure 6b: Comparative quarterly performance of Risk adjusted Visual acuity outcome of LASIK surgery (Uncorrected visual acuity (UCVA) >=6/12 at 6 months post-op ) Quaterly Performance of Doctor A (lower 95% CI, Upper 95% CI) Quaterly Performance of Doctor B (lower 95% CI, Upper 95% CI) Q1 Q2 Q3 Q4 Period Q1 Q2 Q3 Q4 Period Quaterly Performance of Doctor C (lower 95% CI, Upper 95% CI) Quaterly Performance of Doctor D (lower 95% CI, Upper 95% CI) Q1 Q2 Q3 Q4 Period Q1 Q2 Q3 Q4 Period 15

16 Page 16 of Conclusion We measure the performance of LASIK surgery services provided by Optimax Eye Specialist Centre. The surgical service was provided by 4 surgeons at its TTDI branch. Three performance measures were selected, (1) Post-operative Uncorrected visual acuity. (2) Post-operative refraction within +0.5 D of target refraction and (3) Worsening of visual acuity post-op, a measure of patient safety. The performance results achieved by Optimax in 2010 were excellent. The mean success rate (defined as UCVA at 6-month post-op 6/7.5 or better) among the 4 surgeons was 95%, and 99% for UCVA 6/12 or better. Their risk adjusted success rate varies from 93% to 97% ; all 95% confidence intervals overlap 100% success rate. For UCVA 6/12 or better, all surgeons uniformly achieved 99% risk adjusted success rate. The on-target refractive error correction rate (defined as MRSE at 6 months within + 0.5D of Target=0) was 91%; for correction of spherical error alone, the on-target rate was higher at 95%. The safety record of LASIK surgery as provided by Optimax was excellent. No patient has suffered any significant loss of visual acuity as a result of LASIK surgery at 6 months post-op. All patients had a final BCVA better than 6/12 at 6 months post-op. Caution is however warranted in interpreting and using the performance results reported here. The results were based on data collected retrospectively and the risk model used requires further refinement. These results however have established a sound scientific basis and operational experience for the Optimax eye healthcare group to embark on routine prospective measurement of the performance LASIK surgery services. This has been initiated since January

17 Page 17 of 22 Appendix Glossary This section defines the various technical terms found in this protocol/ report in simple nontechnical language for the benefits of readers unfamiliar with the subject matter under investigation. Accountability Astigmatism Epi-LASIK Healthcare providers Hyperopia INTRALASIK LASEK The requirement that healthcare providers who have voluntarily taken on the responsibility to provide healthcare services and are so accredited or licensed, and to whom the necessary authority and resources are provided in order for them to discharge their responsibility, be held answerable for results One form of refractive error where the focusing power of the eye is only affected in one meridian than it is in another. The Epi-LASIK procedure employs a unique microkeratome, called the Epikeratome, to mechanically separate the epithelium from the stroma, creating a flap of epithelial cells only (Epi-flap). Unlike LASIK, no sharp blades or knives are required and unlike LASEK, no alcohol is required. The Epi-flap is moved aside so that the laser can reshape the exposed cornea. After laser application, the Epiflap is replaced over the corneal bed and a bandage soft contact lens is placed on top at the end of procedure. Refers to both institutional providers of health care services (e.g., clinics, hospitals, nursing homes) and clinicians (e.g., physicians, nurse practitioners, nurses, physician assistants). One form of refractive error where the optical power of the eye is too weak to focus light on the retina. This can arise from a cornea with too little curvature or an eyeball that is too short IntraLASIK is a procedure that similar to LASIK where corneal flap is created for laser ablation. However in this procedure, flap is created using femtosecond laser instead of mechanical blade (microkeratome) The procedure uses a software to direct the Femtosecond laser to optically focus its beam into a tiny, 1 micron (.001mm) spot of energy that passes harmlessly through the outer layers of the cornea until reaching its exact depth within the stroma (central deeper layer of the cornea). The laser beam creates a separation plane by forming an interconnecting series of bubbles made of carbon dioxide and water vapor. The laser beam stacks a pattern of bubbles along the periphery of the treatment plane, leaving a separated section of tissue to act as a hinge. As with a traditional LASIK approach, the surgeon then folds the tissue back to expose the underlying corneal layer to prepare for the excimer laser treatment that will re-shape the cornea. With All- Laser-Lasik, surgeons can avoid the complications related to surgical blade problems. The Femtosecond laser precisely delivers the laser energy directly to the outer surface of the eye, which suffers no trauma. Laser epithelial keratomileusis or LASEK is a modified form of photorefractive keratectomy (PRK). This procedure requires the 17

18 Page 18 of 22 LASIK Myopia Performance Performance measure Refractive error Refractive surgery Risk adjustment Visual acuity outer layer of the cornea- epithelium to be loosened with the diluted alcohol solution for around 30 seconds. Then the loosened epithelium (Epi-flap) is moved aside so that the laser can reshape the exposed cornea. After laser application, the Epi-flap is replaced over the corneal bed and a bandage soft contact lens is placed on top at the end of procedure. Laser-assisted in situ keratomileusis A surgical procedure for the correction of refractive error. A circular superficial cornea flap is made initially with a mircokeratome (a special steel blade). The flap is then folded back to allow a type of laser (excimer laser) to ablate and reshape the deeper layers (stroma) of the cornea according to the patient s spectacles prescription. Following laser ablation, the flap is repositioned and will adhere itself naturally without the need for stitches. One form of refractive error in which the focusing power (refraction) of the eye is too strong such that when viewing distant object, the image of the viewed object is brought into focus in front of the retina rather than on it. Myopia can arise from a cornea with too much curvature or an eyeball that is too long The activity of a healthcare provider intended to accomplish the goals of healthcare. These goals are healthcare should be safe, effective, patient-centered, timely, efficient, and equitable. Performance Measures are those measures of process, structure, efficiency, or outcome that have been developed using rigorous methodology, and are intended not only for clinical quality improvement but they have attributes rendering them suitable for public reporting, explicit comparisons of care between healthcare providers, accreditation, pay for performance programs, or other forms of accountability. An error in the focusing of light on the retina (this is back portion of the eye) and a frequent reason for reduced visual acuity. Changing a patient s optical measurements for the purpose of correction of refractive error by means of an operation A process that modifies the analysis of performance measurement results by those elements of the patient population that affect results, are out of the control of providers, and are likely to be common and not randomly distributed Acuteness or clearness of vision. It is often measured according to the size of letters viewed on a Snellen chart List of Abbreviations AvSR Average Success rate BCVA Best Spectacle Corrected Visual acuity CDM Clinical Data Management CER Cylindrical Error CI Confidence interval 18

19 Page 19 of 22 CKAPS CRA CRF CRM D DBMS EC ecrf EDC ESR HPG HPMRS IC ICT ID IEC IQR IRB IT/IS JCI KPI LASIK Max Min MOH MRSE N N/A N/K No. OSR QA QC RASR SAP SC SD SDV SE SEQ SER TTDI UCVA Cawangan Kawalan Amalan Perubatan Swasta MOH Clinical Research Associate Case Report Form Clinical Research Manager Dioptre Database Management System Ethics Committee Electronic CRF Electronic Data Capture Expected Success rate Healthcare provider group Reporting System Malaysian National Registration Card or otherwise called the Identity Card Information and Communication Technology Identity Independent Ethics Committee Interquartile Range Institutional Review Board Information Technology and Information System Joint Commission International Key Performance Indicator Laser-assisted in situ keratomileusis Maximum Minimum Ministry of Health, Malaysia Manifest Refractive Spherical Equivalent Number Not Applicable Not known Number Observed Success rate Quality Assurance Quality control Risk adjusted Success rate Statistical Analysis Plan Site Coordinator Standard Deviation Source Document Verification Standard Error Spherical Equivalent Spherical Error Taman Tun Dr Ismail Uncorrected Visual acuity 19

20 Page 20 of 22 Table 7: Performance measures for LASIK surgery 1. Performance measure Post-operative Uncorrected visual acuity Description & Rationale Acuteness or clearness of vision as measured using a vision chart. This is the most commonly used measure to evaluate visual acuity outcome of LASIK surgery services; just as it is the most well accepted efficacy measure in clinical trial of LASIK surgery. Period of care At the time of LASIK surgery and continued throughout the period of care being assessed Denominator All patients undergoing LASIK surgery for correction of myopia at an Optimax centre Numerator Number of patients with uncorrected visual acuity (UCVA) 6/12 or better at 6 months post-op Data sources Patient medical record Operating room record 2. Performance measure Post-operative Refraction within +0.5 Diopters of target Refraction Description & Rationale Measure of the precision of the refractive correction This is the most commonly used measure to evaluate refractive outcome of LASIK surgery services; just as it is a well accepted efficacy measure in clinical trial of LASIK surgery. Period of care At the time of LASIK surgery and continued throughout the period of care being assessed Denominator All patients undergoing LASIK surgery for correction of myopia at an Optimax centre Numerator Number of patients with mean spherical equivalent within +0.5 Diopers of target refraction at 6 months post-op Data sources Patient medical record Operating room record 3. Performance Loss of visual acuity measure Description & Rationale Visual acuity as measured using a vision chart. Loss of 2 or more lines post-op is commonly used to evaluate loss of visual acuity as a measure of patient safety, just as it is the most well accepted safety measure in clinical trial of LASIK surgery. Period of care At the time of LASIK surgery and continued throughout the period of care being assessed Denominator All patients undergoing LASIK surgery for correction of myopia at an Optimax centre Numerator Number of patients with loss of 2 or more lines of Best spectacle Corrected Visual Acuity (BCVA) at 6 months post-op Data sources Patient medical record Operating room record 20

21 Page 21 of 22 Table 8a: Relationship between Visual outcome of LASIK surgery (Uncorrected visual acuity (UCVA) >=6/7.5 at 6 months post-op) and various putative prognostic factors Univariable analysis Multivariable Logistic regression analysis (k included) Multivariable Logistic regression analysis (k excluded) Factors N Odds Ratio P value Odds Ratio P value Odds Ratio P value Age in years < 25 Ref Sex Male Ref Female Myopia, manifest Low- Moderate (<= D) Ref Moderate to High ( > D) Astigmatism, manifest Low- Moderate (<= D) Ref Moderate to High ( > D) Corneal curvature 1333 Mean K

22 Page 22 of 22 Table 8b: Relationship between Visual outcome of LASIK surgery (Uncorrected visual acuity (UCVA) >=6/12 at 6 months post-op) and various putative prognostic factors Univariable analysis Multivariable Logistic regression analysis (k included) Multivariable Logistic regression analysis (k excluded) Factors N Odds Ratio P value Odds Ratio P value Odds Ratio P value Age in years < 25 Ref Sex Male Ref Female Myopia, manifest Low- Moderate (<= D) Ref Moderate to High ( > D) Astigmatism, manifest Low- Moderate (<= D) Ref Moderate to High ( > D) Corneal curvature 1333 Mean K