The American study indicated that the rise in the number of diagnosed cases caused the hike in healthcare costs, not the increase in the average cost of treatment per patient. These cases focused on the 16 most common diseases, including cancer, lung disease, arthritis, mental illness, high blood pressure, hyperlipidemia, lupus, back problems, Type 2 diabetes, and cardiac, skin, endocrine and gastroenteric diseases. From 1987 to 2002, the percentage of obese individuals receiving treatment for hyperlipidemias rose significantly (up from 1.7 percent to 11.3 percent). That same period also saw troubling rises in the incidence of mental illness (from 5.1 to 14.9 percent), for upper digestive tract problems (from 2.9 to 11.2 percent), for Type 2 diabetes (from 7.3 percent to 9.2 percent), and for asthma (from 2.1 to 5.3 percent). As a consequence, health expenditure in the US for an obese patient during that period was $1,244 dollars more than for a patient of normal weight. «We have to think a bit differently when it comes to the factors that raise health costs,» heath economist Antonis Karokis told Kathimerini. «The burgeoning cost seems to be influenced more by the increase in disease than by the number of people who require health services. This means that health policy must focus more on public health and less on purely economic management.» However, Karokis said changes in the epidemiological pattern may not be as great as they seem. «People are better informed and more willing to seek help, and criteria for diagnosis have changed,» he said. «Modern guidelines set stricter limits for what is considered to be normal blood pressure and blood lipid levels, which means there is a rise in the number of people receiving treatment.» Likewise, the discovery of new drug treatments has led to a rise in the number of cases that are diagnosed and treated.