Note from the National Guideline Clearinghouse (NGC): The National Institute for Health and Clinical Excellence (NICE) commissioned an independent academic centre to perform a systematic literature review on the technology considered in this appraisal and prepare an assessment report. The assessment report for this appraisal was prepared by the West Midlands Health Technology Assessment Group, Department of Public Health and Epidemiology, The University of Birmingham (see the "Companion Documents" field).
Clinical Effectiveness Review
Data Sources
As the authors of the Assessment Report had completed a systematic review on the same subject within the previous year, no formal scoping search was undertaken. This systematic review was used as the basis for the protocol for this technology assessment, which was undertaken in accordance with the pre-defined protocol. The following sources were searched:
- Bibliographic databases: Cochrane Library 2001 Issue 3; MEDLINE (Ovid) 1993-Aug 2001; EMBASE (Ovid) 1993-Aug 2001; Science Citation Index (Web of Science) 1993-Sept 2001; National Research Register and MRC current controlled trials register - September 2001
- National and international health technology assessment (HTA) sites -- (International Association for Health Technology Assessment [INAHTA], National Horizon Scanning Centre [NHSC], Canadian Co-ordinating Office for Health Technology Assessment [CCOHTA], Danish Institute for Health Technology Assessment [DIHTA], Norwegian Centre for Health Technology Assessment [SMM], July 2001)
- Conference abstracts, (Association for Research in Vision and Ophthalmology [ARVO] 1999, 2000, 2001, European Society of Ophthalmology [SOE] 2001)
- Internet sites (Novartis, Visudyne. [Novartis Ophthalmics, Switzerland])
- Citations of all relevant articles found and the data outline sent to us by Novartis separately from the industry submission.
Inclusion and Exclusion Criteria
One reviewer, using explicit predetermined criteria, made the inclusion and exclusion decisions. These were checked by a second reviewer. Inclusion and exclusion decisions were made independently of the inspection of trial results.
Trials and studies were only included if they met the following criteria:
- Study design: Randomised controlled trials
- Population: Adults with wet age-related macular degeneration (ARMD)
- Intervention: Photodynamic therapy (PDT) using any photosensitive drug
- Comparator: Either no treatment (best supportive care) for subfoveal lesions or laser photocoagulation for juxtafoveal or extrafoveal lesions
- Outcomes: Any of visual acuity, contrast sensitivity, quality of life, side effects of treatment
- Reporting: Only trials where recruitment had closed and which reported follow up results for all or nearly all recruited patients were included
The exclusion criteria were:
- Randomised controlled trials (RCT) that had not finished recruiting
- RCTs that had published only baseline characteristics or follow up results for a small proportion of the trial participants
- Studies carried out on animals
Although items 1, 2 and 3 above were excluded from the analysis of clinical effectiveness, their presence was noted as essential background to the review. Note that although new treatments (anecortave acetate and transpupillary thermotherapy [TTT]) are potential comparators to PDT, it was considered that their development is at too early a stage to merit listing in the inclusion criteria.
Costs and Cost Effectiveness Review
A systematic review of the literature on costs, health economic impact and generic quality of life outcomes of PDT for AMD was carried out. Costs studies include studies reporting primary research on the costs and utilisation of care and cost studies that discuss economic aspects of care and contain useful primary or secondary cost or utilisation data.
The review of economic studies followed the method of Mugford and has subsequently been established in other reviews.
Search
A specific search strategy for information on costs, cost effectiveness and quality of life involved searches of:
- Bibliographic databases: MEDLINE (Ovid) 1993-Aug 2001; NHS Economic Evaluation Database (NHS EED) and the NHS Database of Reviews of Effectiveness (DARE)
- Internet sites of national economics units
Relevant information found during the clinical effectiveness searches was also used. Any economic analysis submitted as part of the Industry submission to NICE could also potentially be included.
The search was broadened to find information to inform the economic model. Searches focused on finding relevant economic information on laser photocoagulation and other possible treatments for AMD, the natural course of wet AMD without treatment and of the consequences of blindness.
Inclusion and Exclusion Criteria, Data Extraction and Quality Assessment
One reviewer, using explicit predetermined criteria, made the inclusion and exclusion decisions for the cost effectiveness review and this was checked by a second researcher. Studies were only included if they met the following criteria:
- Study design: Any study type
- Population: Adults with any AMD
- Intervention: PDT using any photosensitive drug
- Outcomes: Costs, cost consequences, cost utility, cost effectiveness or any generic quality of life
One researcher extracted data from the included studies and a second researcher again checked this.
There were 3 stages used for the review of cost and economic studies. In Stage 1 each study was categorised by one of the investigators on the basis of its title and abstract where available, according to five classification criteria. Studies that were categorised into the relevant classification for this review proceeded to Stage 2. In Stage 2 all potentially relevant studies were read in full and further classified. All papers confirmed as being relevant to this review proceeded to Stage 3. In Stage 3 all relevant articles were assessed according to predetermined quality criteria. The quality of the economic evaluations was assessed according to predetermined criteria. The quality of the cost studies was assessed using predetermined criteria.