For patients, simpler is better. "Finish abx as prescribed" is better than pontificating about 3 vs 5 vs 7 days to the patient. 

If patient asks, "I follow this guideline and this is currently recommended. If you still don't feel great after the course, let us know and we will see what else we can do." 

I think it's up to us as clinicians to determine 3 vs 5 vs 7 days. 

I trust this guy for the most part. https://www.bradspellberg.com/shorter-is-better

And here I treat diabetic foot ulcers for weeks…

That dogma is so the patient, confident that they ARE better because they FEEL better after 24hrs, doesn't stop their antibiotics earlier than recommended. It's not because the medical establishment is always overestimating the necessary course length.

My mantra is "vanc/cefepime until ID tells me to quit being a dummy"

Patients should finish their antibiotics regardless of the duration specified (3/5/10/14/30), which isn't something they have to worry about (that's something we tell them).

The advice to always finish antibiotics applies to a 3 day, 5 day, 7 day, 14 day or any other course duration.

I mean, is this question more about considering adjusting prescribing habits or adjusting patient communication? I'd say regardless of what abx duration you think is appropriate, communicating to the patient to complete the whole thing will be the most important part. If guideline recs say 3 days is enough, cool, 3 days is enough, still make sure the patient understands they need to actually take the entire 3 days.

Personally I'd rather see a prescription come through as "for three days until gone" instead of "for up to 5 days, stop after 3 days if symptoms resolved" cuz then I'm gonna call you asking to make up your mind, and neither of us wanna deal with that.

The instructions we give are, "Finish the entire antibiotic prescription unless your doctor tells you otherwise."

If they feel better before the course is complete, they can talk to their doctor, who will advise them if it's appropriate to stop yet. The doctor can make that decision based on the details of the guidelines, the patient, and the infection.

It's not reasonable to expect the average patient to have enough detailed knowledge to make the decision independently.

The dogma is as true as it's always been.

Patient still should complete the entire course of antibiotics to avoid resistance/partially treated infections.

But if we, as a field, decide that the total duration needed for CAP is shorter than previously thought, that's great. We just saved 1000s of antibiotic doses per year. Patient should still finish the full course prescribed for the same reasons we told them before: to reduce partially treated infection and to reduce breeding resistance.

Shorter recommended durations won't change any of that.

My take: The risk of stopping a course of antibiotics prematurely is proportional to the risk of treatment failure and a resurgence of the infection. For straightforward cellulitis, it's probably fine to stop a couple days early if all erythema and tenderness have gone away. If it starts to comes back, it should be immediately obvious to the patient. Cystitis with risk factors for complications, be careful. I've seen those turn into pyelo and epididymo-orchitis. Prosthetic joint infection, not a chance. Take your dang antibiotics.

ancef qd forever acts as an antidepressant... for your orthopod.

Apparently a minority opinion here, but "always finish your antibiotics" is terrible advice. It leads to unnecessary side effects and prolongation of disruption to the microbiome. There are plenty infections for which full resolution of symptoms is a good indicator of its microbiological resolution. (Patients can arbitrarily continue antibiotics for 2-4 doses beyond full symptomatic resolution to "be safe".) The notion that the prescribing clinician picks the duration from the accepted range and the patient needs to follow it to the letter implies that the clinician has clairvoyance as to how quickly the patient will respond. But we are not that good.

As OP points out, medicine has been collectively giving patients courses that are too long for decades. It's absurd to say that patients must be wrong when they stop antibiotic courses early when we were commonly giving 14 days of abx for routine CAP in a healthy person 20 years ago. Was a patient with CAP who stopped abx after just a week during that era wrong to have done so? No, in retrospect they were usually objectively correct. But even in IDSA' 2000 guidelines on CAP (https://pmc.ncbi.nlm.nih.gov/articles/PMC7109923/ ), they recommended continuing abx in uncomplicated pneumococcal pneumonia for 3 days after fever resolution - which in an outpatient would have required the patient's daily self-assessment.

It's a different story for infections for which symptom resolution is not a reliable guide of microbial resolution (e.g. osteomyelitis, endocarditis), but even in those cases we rarely actually know the best duration. 4 weeks vs. 6 weeks vs. other is usually little more than an educated guess biased by decades of made-up historical precedent.

5 days for sinus infections or 7 days for otitis vs 10....it's all viral anyway, why would it ever make a difference?

If we were able to study this on specifically CONFIRMED bacterial infections to begin with at baseline, then we'd have better understanding of the duration that is adequate.

UTIs might be a different situation because we actually get culture and sensitivity data from these. I always do the 7 days Bactrim or Keflex. Why? Because if you say 7 they do 5. If you say 5, they do 3.

Most ID medical dogma lacks nuance or was straight up wrong. Stopping antibiotics when they feel better is fine for nearly all non-severe conditions where the antibiotics are just treating symptoms anyway.

I don't really understand the question. By 'finishing' antibiotics we mean taking the whole 'course', that is however many we prescribe, not however many are in an arbitrary box. If we prescribe them for 5 days then the patient should finish the five days, if we prescribe them for three days based on more recent evidence then 'finishing' them means taking them for three days.

Review the literature and use clinical gestalt. The literature gives a range, use it imo. Fever taking longer to clear than anticipated, symptoms taking a longer time than usual to improve, severe infection, o2 not improving, inflammatory markers/procal still plateaued/not downtrending as anticipated, immune compromised, aberrant anatomy or poor blood flow, recurrent infection tc any number of reasons i may shoot for middle of the road or longer duration especially if what im worried is directly addressed on UTD for longer course. For run of the mill infections in healthy patients especially if rapidly improving will usually shoot for short end of recommended duration. I also have no problem stopping antibiotics that were improperly started which is not a small number these days 🤷🏻‍♂️. Also wild seeing how differently adult ID and peds ID handle things, outcomes are fine both styles so best practice likely somewhere in the middle