Melba's work over the past 18 years includes a broad public policy portfolio in health and social welfare, in both an Executive and Non-Executive capacity. It has consisted of work in the statutory and voluntary sectors. Melba assumed the chairmanship of Wandsworth Primary Care Trust in April 2002. Previously, she was a Non-Executive Director of South West London & St. George's Mental Health NHS Trust. She worked for Mind as Policy Officer, Race & Mental Health Adviser and finally, as Policy Director during a six-year period.
Melba is currently Deputy Chair of the London Health Commission. Melba is also Co- Director at the Centre for Mental Health Services Development England, King's College London, where she undertakes ongoing public policy and service development work with bodies which include The King's Fund, as well as with black and minority ethnic community groups.
She is also involved in various government working groups, including the London Race Equality Group and the NHS Appointments Commission's Advisory and Black and Minority Ethnic Advisory Groups. A former journalist, Melba has written widely on issues of health and social care, with particular reference to black and minority ethnic communities