How patients are seeing their doctor is changing, and that could shape access to and quality of care for decades to come. More than 100 million Americans don’t have regular access to primary care, a number that has nearly doubled since 2014. Yet demand for primary care is up, spurred partly by record enrollment in Affordable Care Act plans. Under pressure from increased demand, consolidation, and changing patient expectations, the model of care no longer means visiting the same doctor for decades. KFF Health News senior correspondent Julie Appleby breaks down what is happening — and what it me…