Not All Claude Is the Same Claude: A Clinician’s Field Test
I asked Claude three clinical questions at three price points. The difference between Free and Max is not a marketing claim. It is a clinical one. Here is the evidence.
A colleague asked me last week whether Claude was worth paying for. She was using the free version and getting answers she described as decent. I told her the question was wrong. The question is not whether free Claude is decent. The question is whether decent is good enough when you are managing a 29-week preeclamptic patient at 2 a.m.
I decided to find out.
I took two real clinical scenarios and asked them across three tiers of Claude:
Free, Pro, and Max.
What I found is not a sales pitch. It is a clinical observation. And like most clinical observations, the data matter more than the opinion.
What are the tiers?
Claude is the AI made by Anthropic. It comes in several models, and the model you access depends on what you pay. The free tier uses Haiku, Anthropic’s fastest and lightest model. It is designed for quick answers and short tasks. Pro, at $20 per month, gives you Sonnet, a meaningfully more capable model, with five times more usage than the free plan. Max, at $100 or $200 per month, gives you Opus, Anthropic’s most powerful model, with priority access and the highest usage limits.
Think of it like hospital staffing. Free is the intern who has read the textbook. Pro is the senior resident who has also seen the cases. Max is the attending who has seen the cases, read the trials, and is about to tell you exactly why the textbook got it wrong.
For most tasks, free Claude is fine. For clinical reasoning under uncertainty, the tiers are not interchangeable. Here is the evidence.
The scenarios
I chose two cases that most obstetric clinicians encounter: a preeclamptic patient at 29 weeks, and a patient with a prior spontaneous preterm birth at 27 weeks presenting at 18 weeks with a 15-millimeter cervix. Neither is a trick question. Both require real clinical judgment.
I asked each version of Claude: manage this patient, briefly. Then I read what came back.
What Free Claude said
Scenario 1: Severe preeclampsia at 29 weeks
Admit, monitor BP and labs. IV magnesium sulfate for seizure prophylaxis. Antihypertensives if BP is 160 over 110 or higher. Betamethasone for fetal lung maturity. Deliver if maternal or fetal status deteriorates.
Scenario 2: History of preterm birth at 27 weeks, now 18 weeks with cervical length 15 mm
High risk for recurrent preterm birth. Start vaginal progesterone. Consider cerclage given short cervix. Serial cervical length monitoring. Discuss signs of preterm labor. Refer to MFM.
Both answers are correct. Neither is wrong. If you posted either one on a medical board review forum, no one would mark it incorrect. But correct and complete are not the same thing. Free Claude gives you a checklist. It does not give you a clinical argument. It does not tell you why, when, or with what evidence. It does not tell you the 15-millimeter cervix plus prior 27-week birth is not just a risk factor but a dual indication that puts a cerclage placement window in front of you right now.
For a nurse triaging at intake, free Claude is useful. For clinical decision-making at the bedside, it is the floor, not the ceiling.
Subscribe to ObGyn Intelligence to read the Pro and Max responses, and to understand exactly what you are paying for — and whether it matters clinically.
Below, paid subscribers will find the Pro and Max responses to both scenarios, and my analysis of what distinguishes each tier clinically.
