2016 review, Barack Obama claimed that from 2010 through 2014 mean annual growth in real per-enrollee Medicare spending was negative, down from a mean of 4.7% per year from 2000 through 2005 and 2.4% per year from 2006 to 2010; similarly, mean real per-enrollee growth in private insurance spending was 1.1% per year over the period, compared with a mean of 6.5% from 2000 through 2005 and 3.4% from 2005 to 2010. Deductibles and co-payments A contributing factor to premium cost moderation was that the insured faced higher deductibles, co-payments and out-of-pocket maximums. In addition, many employees chose to combine a health savings account with higher deductible plans, making the net impact of PPACA difficult to determine precisely. For the group market (employer insurance), a 2016 survey found that: Deductibles grew 63% from 2011 to 2016, while premiums increased 19% and worker earnings grew by 11%. In 2016, 4 in 5 workers had an insurance deductible, which averaged $1,478. For firms with less than 200 employees, the deductible averaged $2,069. The percentage of workers with a deductible of at least $1,000 grew from 10% in 2006 to 51% in 2016. The 2016 figure dropped to 38% after taking employer contributions into account. For the non-group market, of which two-thirds are covered by PPACA exchanges, a survey of 2015 data found that: 49% had individual deductibles of at least $1,500 ($3,000 for family), up from 36% in 2014. Many exchange enrollees qualify for cost-sharing subsidies that reduce their net deductible. While about 75% of enrollees were "very satisfied" or "somewhat satisfied" with their choice of doctors and hospitals, only 50% had such satisfaction with their annual deductible. While 52% of those covered by PPACA exchanges felt "well protected" by their insurance, in the group market 63% felt that way. Health outcomes According to a 2014 study, PPACA likely prevented an estimated 50,000 preventable patient deaths from 2010 to 2013. Himmelstein and Woolhandler wrote in January 2017 that a rollback of PPACA's Medicaid expansion alone would cause an estimated 43,956 deaths annually. According to the Kaiser Foundation, expanding Medicaid in the remaining states would cover up to 4.5 million persons. A study by the National Bureau of Economic Research found a significant decline in mortality rates in the states that opted in to the Medicaid expansion program compared with those states that did not do so. The study reported that states decisions' not to expand Medicaid resulted in approximately 15,600 excess deaths from 2014 through 2017. Two 2018 JAMA studies found the Hospital Readmissions Reduction Program was associated with increased post-discharge mortality for patients hospitalized for heart failure and pneumonia. A 2019 JAMA study found that PPACA decreased emergency department and hospital use by uninsured individuals. A 2019 paper by Treasury Department economists using a randomized controlled trial (the IRS sent letters to some taxpayers noting that had paid a fine for not signing up for health insurance but not to other taxpayers) found that over the span of two years, obtaining health insurance reduced mortality by 12 percent. The study concluded that the letters, sent to 3.9 million people, may have saved 700 lives. Distributional impact In March 2018, the CBO reported that PPACA had reduced income inequality in 2014, saying that the law led the lowest and second quintiles (the bottom 40%) to receive an average of an additional $690 and $560 respectively while causing households in the top 1% to pay an additional $21,000 due mostly to the net investment income tax and the additional Medicare tax. The law placed relatively little burden on households in the top quintile