The value of informal care in the context of option B+ in Malawi: a contingent valuation approach.

Background: Informal care, the health care provided by the patient's social network is important in low income settings although its monetary value is rarely estimated. The lack of estimates of the value of informal care has led to its omission in economic evaluations but this can result in incorrect decisions about cost effectiveness of an intervention. We explore the use of contingent valuation methods of willingness to pay (WTP) and willingness to accept (WTA) to estimate the value of informal care provided to HIV infected women that are accessing antiretroviral therapy (ART) under the Option B+ approach to prevention of mother-to-child transmission (PMTCT) of HIV in Malawi.