Table 2 Examples of impact evaluations
Shortages of clinical staff and difficulties with accessing care due to transportation costs are major obstacles to scaling up the delivery of ART in developing countries. One proposed solution is home-based HIV care, where drug delivery, the monitoring of health status, and the support of patients is carried out at the home of the patient by non-clinically qualified staff. It is highly uncertain, however, whether this strategy is able to provide care of sufficient quality, including timely referrals for medical care, or whether such a system is cost-effective. Therefore, before implementing home-based care programmes widely it is important that they are evaluated for their (cost-) effectiveness. |
To ensure a fair comparison between home-based and facility-based ART, researchers in Uganda conducted a randomised trial. The study area was divided into 44 distinct geographical sub-areas. In some of these, home care was implemented, while in others a conventional facility-based system continued to be used. The selection and allocation of areas to receive, and not to receive, the home-based care system, was randomly determined. This reduced the likelihood of important differences between the comparisons groups which might otherwise have influenced the study if, for example, the districts themselves had decided whether to implement home-based care, or if decisions had been based on an existing preparedness to implement home-based care. The random allocation system used was also the fairest way of deciding where to start home-based care since each district had an equal chance of being chosen. |
The researchers found that the home-based care model using trained layworkers was as effective as nurse- and doctor-led clinic-based care. |
Mandatory use of thiazides for hypertension in Norway[23] |
As a cost-containment measure, policymakers in Norway decided that thiazides would be prescribed as anti-hypertensive drugs instead of more costly alternatives, in those instances where drug expenses were to be reimbursed. The policy was implemented nationally a few months after the decision was made. Because critics continued to argue that the new policy was unlikely to lead to the expected results, The Ministry of Health sponsored a study to assess the impact of the policy they had implemented. |
The mandatory prescription of thiazides for treating hypertension was implemented across Norway with an urgency that made a planned, rigorous impact evaluation impossible to conduct. However, by accessing the electronic medical records of 61 clinics at a later stage, researchers extracted prescription data ranging from one year before to one year after the new policy was introduced. They analysed the data using an interrupted time-series. Monthly rates of thiazide prescribing and other outcomes of interest were analysed over time to see if any significant changes could be attributed to the implemented policy. Analysis indicated that there was a sharp increase in the use of thiazides (from 10 to 25% over a pre-specified three month transition period), following which the use of thiazides levelled off. |