A first-ever comprehensive estimate of U.S. HIV care retention reveals that more than half of HIV-positive patients had gaps in treatment ranging from seven months to a year or more, according a new study published in the journal AIDS and reported in a University of Pennsylvania statement.

Researchers at the University of Pennsylvania’s Perelman School of Medicine studied 17,425 adults who received care between 2001 and 2008 at 12 HIV Research Network clinics across the country. To determine retention in treatment, researchers calculated the time between outpatient visits and examined the visit record of each patient. Since experts recommend that HIV-positive people have checkups every six months, patients who met this guideline were determined to have “no gaps” in care. Only 42 percent of patients met the “no gap” criteria; 31 percent had one or more gaps in care lasting 7 to 12 months; and 28 percent appeared to have gone without care for more than one year on one or more occasions.

Findings showed that retention in care was greater among women, whites, older patients, men who were infected via sex with men, and patients who began care on Medicare (compared with those on private insurance). Retention was also greater among those who had very low CD4 counts when they entered care.

Members of the research team noted that standardized criteria for determining the appropriate time between visits are needed. This is because patients may require unique plans for care if they are at various stages of the disease or are dealing with other health problems or social circumstances.

The researchers also pointed out that tracking retention in care is complicated by the fact that patients may switch doctors, move frequently, go to jail or become institutionalized. The research team recommended that future studies track patients across those circumstances to provide a fuller picture of retention in care.

To read the University of Pennsylvania statement, click here.