Family medicine focuses on CHRONIC care issues and URGENT care issues. Inasmuch as a lot of ER is URGENT care, there is some overlap. However, as an ER resident, you get NO training in CHRONIC care issues.
ER residents don't get experience in neonatal resuscitation. Yes, it is good for us to know, but outside of your few deliveries on OB (requirement for residency is 10 deliveries), you don't focus on this much. In your average ER, a baby is delivered once every few years, so you are unlikely to ever be present with a kid that needs resuscitation in your entire career.
ER residents don't know milestones for pediatric development. I have four kids and I still don't know, or care much about pediatric milestones (as mine are all like me, very advanced).
We don't know what to do about poor feeding, poor weight gain, alternative vaccination strategies, FLK (funny-looking kid ) work-ups. We don't deal with breast-feeding issues, or strategies to help mothers successfully breast-feed. We don't know when to refer kids to specialists (ENT for ear-tubes, urology for UTIs, cardiology for heart-murmurs, allergy-immunology for asthma or allergies, GI for GI issues, geneticists for FLKs). ER doctors don't know jack about formula options, when to switch, when to supplement, when to give vitamins. We don't know what to screen for, or focus on with well-child visits.
We don't give safety lectures (except when for example they come to the ER after an accident and we tell them, "next time, they need to wear a helmet, right?" or "Next time, they'll be in a seat-belt, right?" We don't have primary prevention strategies. We don't give advice on parenting, or screen kids for ADD, or decide when to be concerned about school performance, or when to start Adderall. We don't care about Tanner staging, or why it matters, or when to be concerned.
We don't treat male pattern baldness, erectile dysfunction, and we don't know when to treat with testosterone supplements, or even when to screen for low testosterone.
We don't treat menopausal symptoms, or know indications for hormone replacement. We don't screen for ovarian cancer, cervical cancer, or know what to do with an abnormal result if we got one, other than refer to someone else. We don't screen for osteoporosis, nor would we know how best to treat it. We don't do contraception. There are literally a hundred different birth control options and I have NO clue which to use and why. My advice out of the ER, is wear a condom until you see your PCP.
We don't deliver babies much- raise of hands, how many babies have you delivered in the past year (in the ER)? We don't do much third trimester care, other than scream at the woman on her way up to OB to keep her legs closed. We might see MVAs, and traumas and after-hours urgent care-type third trimester, but primary OB issues after 20 weeks, we are pretty clueless.
We don't screen for, treat, or really care about depression. "Do you want to be admitted to psych? Did you just say the S word? OK, we have to draw some labs, cause that is what the psych doctors like, and we'll try to get you a bed on the psych unit sometime in the next week. Next patient." We all know that SSRIs are used a lot, and sometimes SNRIs, but the cocktails that people come to our ER on usually don't make a whole lot of sense. Why should we even prescribe a medication that doesn't take effect for 2 weeks? Anxiety, depression, eating disorders, and what to do about them is not in our scope. A good FP, or PCP is a councilor to their patients, and has an arsenal of simple, quick behavioral modifications, and if nothing else, some good books, or pamphlets to distribute. If I have time, I might give a pseudo-pep talk, or a fatherly lecture to a patient I think wouldn't get @#!*% off about my advice, but I have NO formal training in the psychiatry, or psychology since med school.
We don't screen for alcohol abuse, unless the patient is there for an alcohol-related emergency. We don't screen for tobacco abuse (sure, the nurses and I might chart it, but the nurses do it because it is a JHACO regulation, and I do it for billing purposes.) Neither myself nor the ER nurse care about the answers. We don't EVER help people get off tobacco. OK, I've written the occasional prescription for a medication that somebody requested I write, but I have NO formal training in assisting people in stopping smoking.
I don't screen for prostate cancer. I don't even attempt to feel for a prostate. In fact, my short stubby fingers would miss huge prostate tumors. I don't know the indications for a PSA, or what to do with the results, or when to refer to urology. I don't screen for breast-cancer, I don't do breast exams, nor would I know the proper work-up of a mass I felt. I don't screen for colorectal cancer.
We don't know anything about dieting, or weight-loss strategies, or indications for medical therapy, or when it is appropriate to refer for bariatric surgery.
We don't monkey with chronic treatment of asthma. In the ER, if we see an asthmatic for an acute exacerbation, oral steroids are almost always given. If you are a PCP, you want to MINIMIZE oral steroid use if possible. We don't receive any training on the various and sundry different non-Beta agonist and non-oral steroid medications. I get the impression that it is slightly more complicated than "give them Advair."
We don't treat chronic HIV.
We don't screen for skin cancer, or do wart removal, or simple mass excisions (not an emergency). I went three years in residency without even removing a toe-nail.
ER doctors are seriously lacking in dermatology issues. If it is hives, we give Benadryl and maybe oral steroids. Pick up a dermatology book, and tell me that isn't intimidating. A good PCP can keep most moles, rashes, and lesions out of the dermatologists office.
Sports medicine we do get some training in, but it is mostly acute fracture care, and acute sprain care. Honestly, I've stopped testing for the ACL in knee injury. They are usually in so much pain acutely, that I don't want to @#!*% off the patient by making them miserable. What does it matter if they did tear their ACL? I can't do anything about it. I have NEVER diagnosed iliotibial band syndrome. I have never seen shin splints in the ER, I don't think that I have ever seen or diagnosed more than a handful of stress-fractures. I don't treat or follow tendonitis. Sports medicine is much more complicated than, RICE. I just don't care about chronic musculoskeletal problems. That is bread and butter of clinic practice.
There are some really cool rheumatologic diseases and work-ups that are straight out of House episodes. We have no clue on how to proceed out of the ER. Is the joint infected? If not, NSAIDS and FU with PCP. ANCAs, RAs, ANAs, blah, blah, blah, don't know, don't care, refer to rheumatology. Again, a good PCP does a lot of the work-up themselves and manages these various diseases alongside specialists to palliate, cure, and manage chronic rheumatologic conditions. Me, I'm not going to even attempt to dabble in that stuff.
We have no neurology rotation in ER (neurosurgery yes, neurology no). The work-up and differential diagnosis of movement disorders is something that I've never attempted in the ER. I've never diagnosed anybody with MS.
"My TSH is high, where do I go from here?" I don't know, I could look it up, but I have literally NEVER decided when to start someone on thyroid medication. I have never worked up, diagnosed, and treated ANY endocrinologic problem. I order a TSH once in a while out of the ER if the symptoms kind of fit, but the level is usually not available in the ER, and my patients are told to follow-up with their PCP for the results. I wouldn't even guess what appropriate incremental increases or decreases are in trying to regulate somebodies thyroid medication.
Chronic coumadin therapy- If I find somebody is high, I tell them not to take their coumadin today and to FU with their PCP in the morning. If they are low, I might tell them to bump it up for 2 days, but then I ask them to FU with their PCP. Who's going to be better at anticoagulation? An ER doc, who has never done much more than occasional tinkering, or a PCP, who has regulated and found that perfect dose on hundreds of patients after thousands of individual adjustments?
Treatment, differential diagnosis of dementia, and work-up and pharmacologic therapy is something we don't broach in ER.
I don't even treat chronic hypertension. The dozens of different options, combos, cost, indications and contraindications, laboratory monitoring, etc. I wouldn't trust an ER doctor to manage. OK, I can tell someone to start HCTZ, and to add an ACE and double it, but after that, I wouldn't hope to become proficient at unless I did a residency. Same thing with cholesterol medication. It seems a lot of people are on statins, so I guess I'd use those a lot, but my knowledge about cholesterol treatment, and goals peaked in med school and has been on a down-hill slide ever since.
These are just the issues I'm aware that my knowledge is deficient in. I'm sure there is a massive fund of knowledge that I don't even know about that is vital to being a good primary care physician.
The huge elephant in the room is that I don't know the first thing about staffing an office, patient flow, goals for recruiting patients, finances of running a clinic, etc. That is a lot of what you learn in PCP residencies, how to survive financially. I can go study for a couple years and come up with most of the above answers, but that is all useless if my practice folds because of bad practice management.
None of my CME time is devoted to any of the above issues. All of FP and PCP literature is. The further I get from medical school, the less I remember about the above issues, and the more I devote to issues primarily important to the ER. In 20 years, I would DEFINITELY have to go do an FP or IM or Peds residency to be an effective PRIMARY CARE PHYSICIAN. Me in a PCP role? Dude, it would be malpractice on a daily basis.
neither do most FPs in my experience. 
