# Preop Eval vs EBM Stats Calc

The clearest difference is rating: Preop Eval at 5.0 against EBM Stats Calc's 4.5. Preop Eval also leads on update cadence (every 6 months vs every 14 months). EBM Stats Calc's advantage is review sentiment (100% vs 67%) and device support (3 vs 1). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Preop Eval holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 2 and 2 respectively. Written reviews complicate that: 67% of Preop Eval's written reviews are positive against 100% of EBM Stats Calc's, so the app with the better star average is not the one people write more warmly about.

Preop Eval ships an update every 6 months, EBM Stats Calc every 14 months. The most recent releases landed on September 30, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | Preop Eval | EBM Stats Calc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/preop-eval/id374154834/reviews)** | [4.5 (2 ratings)](https://appshunter.io/ios/app/ebm-stats-calc/id1329546106/reviews) |
| Number of ratings | 2 | 2 |
| Positive reviews | 66.7% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 months** | Every 14 months |
| Monetization | Free | Free |
| Size | 15 MB | 1 MB |
| Requires iOS | 16.6 | **13.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 17+ | 12+ |
| Developer | [United Health Services, Inc.](https://appshunter.io/developer/1451318916) | [Joshua D. steinberg](https://appshunter.io/developer/374154837) |

## What reviewers say

### Preop Eval

[App page](https://appshunter.io/ios/app/preop-eval/id374154834)

This app provides guidance for evaluating and preparing adult patients for non-cardiac surgery. It includes algorithms and resources on medication management, cardiac event timing, and preoperative testing, serving as both a reference and a teaching tool for medical professionals.

**Highlights:** Cardiac evaluation algorithm, Medication guidance (starting/stopping), Surgery timing after cardiac events, Preoperative testing recommendations, Review for students and residents, Perioperative insulin management

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### EBM Stats Calc

[App page](https://appshunter.io/ios/app/ebm-stats-calc/id1329546106)

This medical app assists clinicians and educators in performing complex calculations related to evidence-based medicine. It offers tools for calculating NNTs, diagnostic test utility, and understanding the impact of pretest probability on posttest results.

**Highlights:** Calculate Number Needed to Treat (NNT), Calculate diagnostic test utility, Pretest to posttest probability conversion, Positive and Negative Predictive Value calculation, Interactive slider for pretest probability demonstration, Useful for clinicians, students, residents, and educators

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Preop Eval free?

Preop Eval is free to download, with no in-app purchases.

### Is EBM Stats Calc free?

EBM Stats Calc is free to download, with no in-app purchases.

### Which has better reviews, Preop Eval or EBM Stats Calc?

Preop Eval is rated higher. Preop Eval averages 5.0 out of 5 from 2 ratings, while EBM Stats Calc averages 4.5 from 2 ratings.

### Do Preop Eval or EBM Stats Calc have ads?

Neither Preop Eval nor EBM Stats Calc shows ads.

### Which is updated more often, Preop Eval or EBM Stats Calc?

Preop Eval ships an update every 6 months, and EBM Stats Calc every 14 months. Most recently, Preop Eval was updated on September 30, 2026 and EBM Stats Calc on October 12, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*