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Directly observed therapy for treatment completion of pulmonary tuberculosis: consensus statement of the Public Health Tuberculosis Guidelines Panel |
Chaulk C P, Kazandjian V A |
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Authors' objectives To evaluate the relative effectiveness of directly observed therapy (DOT), compared with other interventions, in achieving treatment completion for pulmonary tuberculosis.
Searching MEDLINE was searched from 1966 to August 1996 for English language publications using keywords and phrases.
Study selection Study designs of evaluations included in the reviewRandomised or semi-randomised trials, prospective non-randomised studies, retrospective or case-control studies, and cross-sectional studies, were eligible for inclusion.
Specific interventions included in the reviewDOT with and without multiple incentives and enablers, modified DOT, and non-supervised therapy.
Participants included in the reviewThe participants comprised patients with active pulmonary tuberculosis from a variety of population types. These included alcoholics, substance abusers, incarcerated patients, homeless persons and HIV-infected patients.
Outcomes assessed in the reviewThe treatment completion rates and rate of relapse were assessed.
How were decisions on the relevance of primary studies made?Each eligible article was structurally reviewed by at least two panel members for study design, sample size, evaluation methods, and treatment completion as the outcome.
Assessment of study quality Validity was assessed by a structured review, based on the following criteria: study design, sample size, interventions (supervised or non-supervised therapy), target population, drug resistance, and treatment completion as an outcome. Studies were graded for scientific quality according to a published system. The intensity of directly observed therapy was examined and quantified. Studies relating to treatment completion for preventive therapy were excluded from the review.Each eligible article was structurally review by at least two panel members for study design, sample size, evaluation methods, and treatment completion as the outcome. The full panel was convened twice with intercurrent small group meetings, conference calls, and a summary workshop to review the findings. Recommendations made through this process were drafted by the panel chair and circulated twice for additional comments from the panel.
Data extraction Each eligible article underwent structured review by at least two panel members for study design, sample size, evaluation methods, and treatment completion as the outcome. The full panel was convened twice with intercurrent small group meetings, conference calls, and summary workshop to review findings. Recommendations made through this process were drafted by the panel chair and circulated twice for additional panel comments.
The following data were also tabulated: source; incentives and enablers; sample size; setting; drug resistance; the proportion completing therapy; other outcomes; and the level of evidence.
Methods of synthesis How were the studies combined?The studies were combined in a tabular format and in a narrative review, with a summary of the percentage ranges for the outcomes of treatment completion and relapse.
How were differences between studies investigated?The studies were graded according to quality of evidence using a published system. The grading for each study was shown in the tables. The results were reported according to the type of treatment.
Results of the review Twenty-seven with a total of 274,773 participants were selected: 5 randomised or semi-randomised trials (3,823 participants), 12 prospective trials without controls (4,395 participants), 7 retrospective studies (4,679 participants), 2 case-control studies (670 participants) and 1 cross-sectional report (261,116 participants).
The 12 studies based on comprehensive DOT using multiple incentives and enablers reported the highest treatment completion rates, ranging from 86 to 96.5% (median 91%). The rate of tuberculosis relapse ranged from 0 to 11.5%. The 4 studies of DOT without incentives and enablers reported treatment completion rates ranging from 85 to 87.6% (median 86.3%), with relapse rates ranging from 0.8 to 4.9%. For modified DOT (only partial supervision), the treatment completion rates ranged from 78.6 to 82.6% (median 78.6%). However, caution should be taken in interpreting these results due to the inconsistencies between the text, table and figure. The 9 studies with non-supervised strategies reported treatment completion rates ranging from 41.9 to 82% (median 61.4%), and relapse rates ranging from 2.1 to 4.5%.
Cost information Two studies concluded that DOT was more cost-effective than self-administered therapy (SAT). In one study, the cost per case cured was US$13,925 for DOT, compared with US$15,003 for SAT. In the other study, the cost per case cured was US$3,999 for DOT, compared with US$12,167 for SAT.
Authors' conclusions Treatment completion rates for pulmonary tuberculosis are most likely to exceed 90%, as recommended by the Centers for Disease Control and Prevention, when treatment is based on a patient-centred approach using DOT with multiple enablers and enhancers. Other less intensive interventions are less likely to achieve this recommended treatment completion goal. DOT also appears to be cost-effective compared with SAT, although data on the cost-effectiveness are limited.
CRD commentary The review adequately stated its objective, interventions, participants, outcomes, inclusion and validity criteria, methods of data extraction, and assessment of differences between the studies. The search strategy was limited. The results included a table showing the median (%) of the results for each treatment type. This table did not reflect the range of percentages given in the text for the modified DOT group: the median (%) shown in the table was identical to the figure given at the beginning of the range in the text.
Funding W. K. Kellogg Foundation.
Bibliographic details Chaulk C P, Kazandjian V A. Directly observed therapy for treatment completion of pulmonary tuberculosis: consensus statement of the Public Health Tuberculosis Guidelines Panel. JAMA 1998; 279(12): 943-948 Indexing Status Subject indexing assigned by NLM MeSH Ambulatory Care /economics; Antitubercular Agents /administration & Case Management /economics; Community Health Workers /economics; Cost-Benefit Analysis; Humans; Patient Compliance; Patient-Centered Care /economics; Practice Guidelines as Topic; Tuberculosis, Pulmonary /drug therapy /economics; United States; dosage AccessionNumber 11998008440 Date bibliographic record published 31/08/1999 Date abstract record published 31/08/1999 Record Status This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn. |
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