| Study characteristics |
| Patient Sampling |
Case‐control study. The cases were selected from a database of more than 400 people with keratoconus recruited for longitudinal videokeratography and genetic studies of keratoconus at the Cedars‐Sinai Medical Center (CSMC), Los Angeles, California. |
| Patient characteristics and setting |
Keratoconus: inclusion criteria included slit‐lamp or retroillumination signs of keratoconus in 1 or both eyes, absence of corneal scarring, no history of contact lens wear of any type, no signs or history of other corneal disease, and no previous ocular surgery. 195 normal control participants were also studied. |
| Index tests |
Regression algorithm. The KISA% index quantifies the topographic features seen in people with clinical keratoconus. |
| Target condition and reference standard(s) |
Topography images were taken of both eyes of each study participant with the TMS‐1. It was unclear how the diagnosis was made. The cases were labelled before the analysis with the algorithm. |
| Flow and timing |
It is unclear if all cases received the same reference standard. All data were included in a 2 × 2 table. |
| Comparative |
Not applicable |
| Notes |
Supported by NIH Grant EY09052 and The Eye Birth Defects Research Foundation, Inc. |
| Methodological quality |
| Item |
Authors' judgement |
Risk of bias |
Applicability concerns |
| DOMAIN 1: Patient selection |
| Was a consecutive or random sample of patients enrolled? |
Unclear |
|
|
| Was a case‐control design avoided? |
No |
|
|
| Did the study avoid inappropriate exclusions? |
Yes |
|
|
| Could the selection of patients have introduced bias? |
|
Unclear risk |
|
| Are there concerns that the included patients and setting do not match the review question? |
|
|
High |
| DOMAIN 2: Index test (All tests) |
| Were the index test results interpreted without knowledge of the results of the reference standard? |
Unclear |
|
|
| If a threshold was used, was it pre‐specified? |
Yes |
|
|
| Was the model designed in an appropriate manner? |
Yes |
|
|
| Could the conduct or interpretation of the index test have introduced bias? |
|
Unclear risk |
|
| Are there concerns that the index test, its conduct, or interpretation differ from the review question? |
|
|
Low concern |
| DOMAIN 3: Reference standard |
| Is the reference standard likely to correctly classify the target condition? |
Unclear |
|
|
| Were the reference standard results interpreted without knowledge of the results of the index tests? |
Yes |
|
|
| Could the reference standard, its conduct, or its interpretation have introduced bias? |
|
Unclear risk |
|
| Are there concerns that the target condition as defined by the reference standard does not match the question? |
|
|
Unclear |
| DOMAIN 4: Flow and timing |
| Did all patients receive the same reference standard? |
Unclear |
|
|
| Were all patients included in the analysis? |
Yes |
|
|
| Could the patient flow have introduced bias? |
|
Unclear risk |
|
| DOMAIN 5: Comparative |
