# Preop Eval vs Opioids Dosage Conversion

The clearest difference is rating: Preop Eval at 5.0 against Opioids Dosage Conversion's 4.3. Opioids Dosage Conversion's advantage is ratings volume (19 vs 2) and review sentiment (78% vs 67%). On price, update cadence, 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 4.3. That said, the two scores are not equally well evidenced: Opioids Dosage Conversion has 19 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 67% of Preop Eval's written reviews are positive against 78% of Opioids Dosage Conversion'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, Opioids Dosage Conversion every 4 months. The most recent releases landed on November 6, 2026 and November 1, 2026 respectively.

## The numbers

| Metric | Preop Eval | Opioids Dosage Conversion |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/preop-eval/id374154834/reviews)** | [4.3 (19 ratings)](https://appshunter.io/ios/app/opioids-dosage-conversion/id382383903/reviews) |
| Number of ratings | 2 | **19** |
| Positive reviews | 66.7% of reviews | **77.8% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 4 months** |
| Monetization | Free | Free |
| Size | 15 MB | 2 MB |
| Requires iOS | 16.6 | **15.6** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 17+ | 17+ |
| Developer | [United Health Services, Inc.](https://appshunter.io/developer/1451318916) | [Chris Marcellino MD LLC](https://appshunter.io/developer/1161719220) |

## 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


### Opioids Dosage Conversion

[App page](https://appshunter.io/ios/app/opioids-dosage-conversion/id382383903)

This app is a calculator for trained medical professionals to convert opioid analgesic dosages. It supports various common opioids and administration routes, offering features like breakthrough dosing and cross-tolerance calculations.

**Highlights:** Opioid dosage conversion, Multiple drug support, Multiple route support, Breakthrough dosing calculator, Incomplete cross tolerance option, Instructional details

**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 Opioids Dosage Conversion free?

Opioids Dosage Conversion is free to download, with no in-app purchases.

### Which has better reviews, Preop Eval or Opioids Dosage Conversion?

Preop Eval is rated higher. Preop Eval averages 5.0 out of 5 from 2 ratings, while Opioids Dosage Conversion averages 4.3 from 19 ratings.

### Do Preop Eval or Opioids Dosage Conversion have ads?

Neither Preop Eval nor Opioids Dosage Conversion shows ads.

### Which is updated more often, Preop Eval or Opioids Dosage Conversion?

Preop Eval ships an update every 6 months, and Opioids Dosage Conversion every 4 months. Most recently, Preop Eval was updated on November 6, 2026 and Opioids Dosage Conversion on November 1, 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.*