The DOTS strategy in China: results and lessons after 10 years.

Research Theme Papers The DOTS strategy in China: results and lessons after 10 years Xianyi Chen,1 Fengzeng Zhao,2 Hongjin Duanmu,2 Liya Wan,3 Lixia Wang,4 Xin Du,5 & Daniel P. Chin6 Objective To analyse the five-point tuberculosis (TB) strategy, DOTS, 10 years after its implementation in one-half of China’s population, and to suggest lessons for future implementation of the DOTS strategy. Methods We analysed trends in case-finding and treatment outcome over time following implementation of the DOTS strategy in each county, using routine reporting data from the Infectious and Endemic Disease Control (IEDC) project (1991–2000). We also determined the proportion of counties with different levels of case-finding for the fifth and sixth years of DOTS implementation. Findings From 1991 to 1995, DOTS expanded rapidly to cover more than 90% of target population and counties. By 2000, 8 million TB suspects had received free diagnostic evaluation: 1.8 million TB cases were diagnosed, free treatment was provided to 1.3 million smear-positive cases, and more than 90% were cured. During DOTS implementation, the percentage of previously treated cases decreased among all smear-positive cases and treatment outcomes improved. Despite these achievements, the detection rate for new smear-positive cases in the project was estimated to be only 54% in 1998, and 41.2% of the counties had a below average or low level of case-finding (with substantial variation between provinces). Conclusions The IEDC project demonstrated that it is feasible to rapidly expand DOTS on a large scale. The global target of an 85% cure rate was quickly achieved, and the level of drug-resistance was probably reduced by this project. However, case-detection did not reach the 70% global target, and more research is needed on how to enhance this. Keywords Tuberculosis, Pulmonary/drug therapy; National health programs/organization and administration; Disease notification; Treatment outcome; Program evaluation; China (source: MeSH, NLM). Mots cle´s Tuberculose pulmonaire/chimiothe´rapie; Programme national sante´/organisation et administration; Notification maladie; Evaluation re´sultats traitement; Evaluation programme; Chine (source: MeSH, INSERM). Palabras clave Tuberculosis pulmonar/quimioterapia; Programas nacionales de salud/organizacio´n y administracio´n; Notificacio´n de enfermedad; Resultado del tratamiento; Evaluacio´n de programas; China (fuente: DeCS, BIREME ). Bulletin of the World Health Organization 2002;80:430-436. Voir page 435 le re´sume´ en franc¸ais. En la pa´gina 436 figura un resumen en espan˜ol. Introduction In 1991, the Government of China introduced a TB control project using the WHO-recommended, five-point strategy calledDOTS. The project, entitled the Infectious andEndemic Disease Control (IEDC) project, was assisted by aWorld Bank loan andwas implemented in 12 provinces with a population of 573million, roughly one-half of China’s population in 1991. An earlier report of this project reported that the programme expanded rapidly over the first four years (1991–94) to cover 80% of the target population (1). Over 200 000 smear-positive TB cases were diagnosed and, more importantly, nearly 90%of new smear-positive cases were identified. Over 80% of previously treated cases were cured. The initial successes of the IEDC project showed that it was feasible to implement the DOTS strategy on a large-scale. In June 2002, the IEDC project will end. It has been the largest TB control project in theworld to use theDOTS strategy, and in this article we summarize the main results of the project and discuss key lessons. This 10-year experience has important implications for China, as it seeks to sustain and further expand DOTS. The results and lessons may also be of interest to other countries as they scale up their implementation of DOTS. Methods The project began in April 1991 with five pilot counties in Hebei province, expanded in April 1992 to 65 pilot counties in all 1 Deputy Director-General, Disease Control Department, Ministry of Health, Beijing, China. 2 Professor, National Tuberculosis Control Center, Beijing, China. 3 Senior Officer, Disease Control Department, Ministry of Health, Beijing, China. 4 Associate Professor, National Tuberculosis Control Center, Beijing, China. 5 Staff, National Tuberculosis Control Center, Beijing, China. 6 Medical Officer, World Health Organization, Beijing, China. Correspondence should be addressed to this author at Room 401, 23 Dongzhimenwai Dajie, Chaoyang District, Beijing 100600, China (email: chind@chn.wpro.who.int). Ref. No. 02-0036 430 # World Health Organization 2002 Bulletin of the World Health Organization 2002, 80 (6) 12 provinces, and thereafter to other counties. Ultimately, the project involved 12 provinces with 1208 counties and a population of 573 million people (1991 population data). Project counties served as demonstration areas and in general they had pre-existing capacity to carry out DOTS. In 1996, Sichuan province split off a municipality called Chongqing. Thereafter, there were 12 provinces and one municipality in the project. To simplify the presentation of data, however, we have reported project results using the old undivided province of Sichuan. The technical approaches of the project have been described elsewhere (1, 2). Briefly, a standardized diagnostic evaluation was provided free of charge to patients presenting to the county or district TB dispensary. Patients meeting symptom criteria were examined by chest fluoroscopy; those with suspicious fluoroscopy findings submitted three sputum samples for smear examination, and chest X-ray examination was performed if indicated. Patients with smear-positive pulmonary TB received standardized intermittent treatment using streptomycin, isoniazid, pyrazinamide, and rifampin; for retreatment cases, ethambutol was added. Sputum specimens were collected at standardized intervals to document sputum conversion and cure. A health care worker, usually the village doctor (also known as a barefoot doctor), was given a case management fee to directly observe the ingestion of drugs. Quarterly reports on case-finding, treatment outcome, and other programme activities were submitted from the county to the prefecture, and subsequently to the province and central level. This reporting system permitted the project to be monitored continually. Supervision and quality control activ- ities, conducted from higher to lower administrative levels, maintained the quality of the programme. An extensive training programme was put into place for health care workers involved in the project, from provincial staff to the village doctors. For each county involved in the project, all data from 1991 to 2000 were analysed by year over the course of DOTS implementation. Time zero was set as the calendar date when each county started implementing DOTS. However, the DOTS implementation data were not analysed by calendar date, since the implementation dates varied between counties. For example, some counties started DOTS in 1992, others in 1993 or 1994. Instead, data collected from each of the counties during the first year they implemented DOTS were referred to as data from the first year of DOTS implementation, and subsequent annual data were numbered consecutively. To assess the effectiveness of case-finding in each province, we first ranked the counties in each province according to their notification of new smear-positive cases during the fifth and sixth year of DOTS implementation (when case notification was highest and nearly all counties had implementedDOTS).We then divided the average case notification rate for the top 10% of the counties into four, to form four quartiles corresponding to 425%, 26–50%, 51–75% and>75%of the top case notification rate. For example, if the average rate in the top-performing counties was 60 cases per 100 000 people, the rates in the four quartiles would be415, 16–30, 31–45 and>45. Finally, for each province, we determined the proportion of its counties in each quartile of case-finding. Results DOTS expansion and coverage The number of counties implementing the DOTS strategy and the population covered in these counties expanded rapidly from five pilot counties in 1991 to more than 90% of the target coverage (by county and by population) by the end of 1995 (Fig. 1). Nine of the 12 provinces reached 90%DOTS coverage by the end of 1994, and 10 of 12 provinces reached 100%DOTS coverage by the end of 1995. Only one province, Sichuan, never achieved 100% DOTS coverage. Eventually, DOTS was made available to 98.9% of the 573 million target population (1991 population data) and 96.1% of the 1208 target counties. Because counties started implementing DOTS at different times, the duration of DOTS implementation for each county also varied. By the end of 2000, 1132 (96.1%) and 1105 (91.6%) counties had implemented DOTS for at least five and six years, respectively. However, only 910 (75.5%) and 581 (48.2%) counties had implemented DOTS for at least seven and eight years, respectively. The mean and median duration of project implementation (up to the end of 2000) was 6.9 and 7.25 years, respectively (range: 0.00–9.75 years; 25– 75% interquartile range: 6.50–7.75 years). Case-finding, 1991–2000 Between 1991 and 2000, 7.99 million patients with suspected TB were evaluated in TB dispensaries; 7.68 million (96.0% of all suspects) received fluoroscopic examination; of these, 3.53 million (45.9%) had suspicious findings on fluoroscopy, and sputum samples were collected and examined for acid-fast bacilli. Overall, 1 299 610 smear-positive pulmonary TB cases and 507 660 smear-negative pulmonary TB cases were diagnosed; 71.7% of pulmonary TB cases were smear-positive. Among the smear-positive pulmonary cases, 908 973 (70.8%) were new cases; 92 277 (7.2%) were relapse cases; and 281 713 (22.0%)were other retreatment cases, which primarily 431Bulletin of the World Health Organization 2002, 80 (6) Ten years of DOTS in China consisted of patients who were treated after defaulting from prior treatment. Although DOTS coverage expanded rapidly, the rate of case-finding increased more slowly (Fig. 1). The notification rate of new smear-positive cases gradually increased by 163%, from 10.3 cases per 100 000 people in 1992, to 27.1 cases per 100 000 in 1998. Over the same period, the notification rate of previously treated cases (relapse and other retreatment) decreased by 39%, from 11.7 to 7.1 cases per 100 000 people. WHO estimated the incidence of new smear-positive cases in China to be 50.7 cases per 100 000 people in 1998 (3). Applying this figure to project areas, the estimated case-detection rate under DOTS for new smear-positive cases (i.e. DOTS detection rate) was 53.5% in 1998. The case-detection rate is the number of notified cases divided by the estimated number of cases in the population of interest. Case-finding following DOTS implementation From the first to the fifth project year of DOTS implementa- tion, the notification rate of new smear-positive cases steadily increased, reaching nearly twice the initial rate (from 13.6 to 26.0 cases per 100 000 people); thereafter, there was little further increase (Fig. 2). The notification rate of previously treated smear-positive cases declined rapidly between the first and second years of DOTS implementation (from 15.1 to 9.4 cases per 100 000 people); thereafter, the decline was more gradual. As a result of a steady increase in the notification rate of new smear-positive cases, and a more gradual decrease in the notification rate of previously treated cases, the percentage of previously treated cases among all smear-positive cases decreased over time until it levelled off at approximately 20% in the seventh year of DOTS implementation (Fig. 2). The decline was greatest from the first to the second year of DOTS implementation, from 52.4% to 37.6%, primarily because of a large decrease in the notification rate of previously treated cases. Finally, the notification rate of smear-positive cases correlated with the rate of TB suspect evaluation. The rate of TB suspect evaluation was high in the first year of DOTS implementation and this was accompanied by a high notification rate of smear-positive cases, including a high notification rate of previously treated cases.When the rate of TB suspect evaluation dropped in the second year of DOTS, the notification rate of smear-positive cases also dropped, but this was entirely due to a decrease in the notification of previously treated cases. After the second year of implementing DOTS, the rate of TB suspect evaluation increased and then levelled off, as did the notification rate of smear-positive cases. Treatment outcome following DOTS implementation Following the implementation of DOTS, treatment outcomes were excellent and improved over time. Overall, the cure rate was 95% and 90% for new and previously treated (relapse and other retreatment) cases, respectively (Table 1). From the first to the sixth year of DOTS implementation, the cure rate for both new and previously treated cases improved, while the treatment failure rate and death rate both decreased. Roughly two-thirds of the eventual improvement in treatment outcomes took place between the first and second year of DOTS implementation. For example, the percentage of treatment failure among new cases declined from 2.8% to 0.5% over the first six to eight years of DOTS implementation, but this percentage declined from 2.8% to 1.2% during the first year alone. Variation in case-finding effectiveness between provinces During the fifth and sixth year of DOTS implementation, which corresponded roughly to the peak of project imple- mentation, there were substantial differences between pro- vinces in case-detection (Table 2). The rate of TB suspect evaluation varied by more than fourfold and the ratio of suspects to smear-positive cases varied by nearly sevenfold. Although the overall percentage of previously treated cases levelled off at approximately 20% following DOTS imple- mentation (Fig. 2), this percentage varied by twofold between provinces. Dividing the notification rate of new smear-positive cases in each province by the notification rate for the top 10%- ranked counties, gave a percentage measure of how the province was actually progressing in case-finding, compared to the achievement of the best-performing counties in the province. During the fifth and sixth year of DOTS implementation, this percentage varied from 37.3% to 73.3% between the provinces (Table 2). 432 Bulletin of the World Health Organization 2002, 80 (6) Special Theme – Tuberculosis For each province, we determined the proportion of counties in four quartiles of case-finding (Fig. 3). Overall, 19.9%, 39.2%, 29.3%, and 11.6% of the counties had respectively >75%, 51%–75%, 26%–50%, and 425% of the case notification rate in the top-performing counties. The percentage of counties in the upper two quartiles of case notification rate ranged from 23.1% to 95.4%. The percentage of counties in the lower two quartiles of case notification rate ranged from 4.6% to 76.9%. Five of the 12 provinces had more than 40% of their counties in the lower two quartiles of case-finding. Discussion Rapid DOTS expansion is feasible A number of lessons for future efforts to control TB in China and other countries can be derived from the results of 10-years’ experience in DOTS expansion and implementation. One is that rapid expansion of DOTS coverage can be achieved: in less than five years, DOTS coverage expanded from zero to more than 90%of target areas and population. Although China was the first large country to successfully expand DOTS coverage rapidly, there are now other examples of this, including the programme in India, where DOTS coverage has expanded rapidly in the past few years (4, 5). WHO recently released the Global DOTS Expansion Plan, which aims to dramatically scale up the implementation of DOTS worldwide by 2005 (6). The expansion that took place in China suggests that rapid global expansion is feasible. Although many factors contributed to the rapid expansion of DOTS in China, we believe two were critical. First, there was political commitment by government leaders to expand DOTS. To oversee the project, project-leading groups (usually led by the Vice-Governor or Vice-Mayor) were formed at every level of government down to the county. The political commitment led to financial commit- ment, as finance bureaux committed to borrow and repay the project loan and provide the necessary counterpart funds. The second factor was the system of TB institutions, from central Table 1. Treatment outcomes for smear-positive TB cases, by year of DOTS implementation Year of DOTS Completed implementation Registered Cured treatment Died Failed Defaulted Transferred Other n n n n n n n n New smear-positive cases 1 77 369 69 461 (89.3)a 1994 (2.6) 1638 (2.1) 2127 (2.7) 1246 (1.6) 265 (0.3) 638 (0.8) 2 88 181 83 013 (94.1) 1320 (1.5) 1340 (1.5) 1081 (1.2) 793 (0.9) 241 (0.3) 393 (0.4) 3 114 362 109 241 (95.5) 1252 (1.1) 1546 (1.4) 925 (0.8) 876 (0.8) 203 (0.2) 319 (0.3) 4 134 877 129 361 (95.9) 1527 (1.1) 1703 (1.3) 888 (0.7) 794 (0.6) 254 (0.2) 350 (0.3) 5 138 883 133 846 (96.4) 1543 (1.1) 1489 (1.1) 792 (0.6) 735 (0.5) 223 (0.2) 255 (0.2) 6 118 914 115 008 (96.7) 1060 (0.9) 1222 (1.0) 584 (0.5) 619 (0.5) 188 (0.2) 233 (0.2) 7 73 547 71 116 (96.7) 678 (0.9) 768 (1.0) 373 (0.5) 357 (0.5) 114 (0.2) 141 (0.2) 8 12 855 124 485 (97.1) 95 (0.7) 118 (0.9) 66 (0.5) 64 (0.5) 7 (0.1) 20 (0.2) 9 556 554 (99.6) 0 (0.0) 2 (0.4) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) All years 759 544 724 085 (95.3) 9469 (1.2) 9826 (1.3) 6836 (0.9) 5484 (0.7) 1495 (0.2) 2349 (0.3) Smear-positive relapse cases 1 18 773 15 415 (82.1) 670 (3.6) 641 (3.4) 1419 (7.6) 319 (1.7) 94 (0.5) 215 (1.1) 2 10 839 9731 (89.8) 277 (2.6) 217 (2.0) 361 (3.3) 126 (1.2) 46 (0.4) 81 (0.7) 3 10 874 9971 (91.7) 232 (2.1) 251 (2.3) 254 (2.3) 98 (0.9) 30 (0.3) 38 (0.3) 4 11 688 10 830 (92.7) 232 (2.0) 237 (2.0) 218 (1.9) 83 (0.7) 27 (0.2) 61 (0.5) 5 11 186 10 444 (93.4) 197 (1.8) 234 (2.1) 203 (1.8) 51 (0.5) 24 (0.2) 33 (0.3) 6 9212 8620 (93.6) 126 (1.4) 196 (2.1) 157 (1.7) 60 (0.7) 14 (0.2) 39 (0.4) 7 5624 5301 (94.3) 62 (1.1) 101 (1.8) 106 (1.9) 30 (0.5) 4 (0.1) 20 (0.4) 8 855 802 (93.8) 12 (1.4) 20 (2.3) 13 (1.5) 3 (0.4) 3 (0.4) 2 (0.2) 9 60 59 (98.3) 0 (0.0) 1 (1.7) 0 (0.00) 0 (00.0) 0 (0.0) 0 (0.0) All years 79 111 71 173 (90.0) 1808 (2.3) 1898 (2.4) 2731 (3.5) 770 (1.0) 242 (0.3) 489 (0.6) Other retreatment smear-positive cases 1 67 154 55 224 (82.2) 2323 (3.5) 2348 (3.5) 4728 (7.0) 1440 (2.1) 174 (0.3) 919 (1.4) 2 42 385 38 499 (90.8) 905 (2.1) 946 (2.2) 1131 (2.7) 567 (1.3) 97 (0.2) 240 (0.6) 3 41 900 38 952 (93.0) 731 (1.7) 835 (2.0) 763 (1.8) 403 (1.0) 70 (0.2) 146 (0.3) 4 36 986 34 467 (93.2) 690 (1.9) 661 (1.8) 666 (1.8) 299 (0.8) 69 (0.2) 134 (0.4) 5 32 125 30 098 (93.7) 626 (1.9) 507 (1.6) 493 (1.5) 215 (0.7) 62 (0.2) 124 (0.4) 6 22 260 20 914 (94.0) 398 (1.8) 339 (1.5) 327 (1.5) 160 (0.7) 33 (0.1) 89 (0.4) 7 10 530 9840 (93.4) 185 (1.8) 168 (1.6) 197 (1.9) 94 (0.9) 21 (0.2) 25 (0.2) 8 1720 1619 (94.1) 19 (1.1) 23 (1.3) 43 (2.5) 15 (0.9) 1 (0.1) 0 (0.0) 9 37 35 (94.6) 0 (0.0) 1 (2.7) 0 (0) 0 (0.0) 1 (2.7) 0 (0.0) All years 255 097 229 648 (90.0) 5877 (2.3) 5828 (2.3) 8348 (3.3) 3193 (1.3) 528 (0.2) 1677 (0.7) Source: IEDC project. a Figures in parentheses are percentages. 433Bulletin of the World Health Organization 2002, 80 (6) Ten years of DOTS in China level down to the county level, which permitted the rapid dissemination and implementation of a single set of technical guidelines for TB control. The same system also permitted a flow of information and resources between administrative levels. Regular reports flowed from lower to upper admin- istrative levels, while project supervision, monitoring, training, and drug distribution flowed from upper to lower adminis- trative levels. High cure rate can be quickly achieved The second lesson from the China project is that a high cure rate can be achieved and maintained during rapid DOTS expansion. As a programme rapidly increases both geographi- cal coverage and the number of patients, it can be difficult to maintain high-quality treatment and case management that result in high cure rates. Low cure rates and increasing drug resistance can develop unless the programme maintains the essential training, supervision, and quality control activities. In China, the quality of treatment was not compromised as the project expanded and the cure rate actually increased and the treatment failure rate decreased. We believe the project maintained a high cure rate because DOTS was implemented as a full package. The political and financial commitment permitted everyone with infectious TB, regardless of financial status, to access high- quality TB treatment free of charge in the TB dispensaries. In addition, the reporting system tracked the availability of drugs in every county so that a stable drug supply was ensured. The recording and reporting system also permitted the continual monitoring of treatment in each county and for each patient. Health care workers were trained in proper case management methods, including how to provide directly observed therapy. Although the use of directly observed therapywas important to ensure a high cure rate, other elements of DOTS were equally important. Difficulty in achieving global case-detection target The third lesson is that a high case-detection rate is more difficult to achieve than either the expansion of DOTS or a high cure rate. In spite of the successful expansion of DOTS, the project did not achieve the global case-detection target of 70%. Although the detection of new smear-positive cases gradually increased over time, the case detection rate reached only about 54% at the peak of project implementation, and we suggest that certain issues should be examined as potential constraints to a high case-detection rate. One issue is why 40% of the counties implementing DOTS were below-average or poor performers in case-finding. Was this due to poor programme management, inadequate human resources, poor staff motivation, financial constraints, poor primary health care infrastructure, lack of community involvement, or other problems? More research, including social assessment and operational research, is needed to determine the reasons for poor case-finding and to identify possible interventions. If targeted interventions can be provided to the more proble- matic counties and they improve their case-finding, this would lead to an improvement in the overall case-detection rate. Another potential constraint to case-finding was the inadequate referral of TB suspects and cases from the hospital system to the TB dispensary (public health) system. According to the 2000 National TB Prevalence Survey, only 12% of TB patients in China received their diagnosis of TB from a TB dispensary (7). The vastmajority of TB cases were diagnosed in the hospital system. Most received some treatment in the hospitals but then failed to complete a full course of treatment. Many eventually reached the TBdispensaries, were classified as previously treated cases and retreated. Therefore, the high percentage of previously treated cases among all cases was a rough indicator of the extent to which hospitals failed to refer newTB patients, and failed to cure those patients they chose to keep and treat. Table 2. Case-finding during the fifth and sixth years of DOTS implementation, by province Province Notification of Notification of previously Ratio of no. Notification rate Suspect new smear- treated smear- of suspects of new smear- evaluation positive cases positive cases evaluated to positive cases Retreatment n Ratea n Ratea n Ratea no. of smear- in top % positive cases 10% countiesb Hebei 68 377 109.5 15 396 24.6 4566 7.3 3.4:1 41.8 22.9 Liaoning 186 656 476.5 6 503 16.6 1569 4.0 23:1 37.6 19.4 Heilongjiang 83 651 237.2 14 295 40.5 2943 8.3 4.9:1 62.5 17.1 Shandong 176 097 203.5 13 479 15.6 4979 5.8 9.5:1 26.4 27.0 Hubei 82 974 149.4 17 540 31.6 6678 12.0 3.4:1 57.8 27.6 Hunan 92 644 145.7 15 763 24.8 6483 10.2 4.2:1 45.1 29.1 Guangdong 135 431 202.4 22 079 33.0 3640 5.4 5.3:1 45.0 14.2 Hainan 21 367 299.5 2559 35.9 457 6.4 7.1:1 60.4 15.2 Sichuanc 159 080 185.7 22 413 26.2 6612 7.7 5.5:1 63.5 22.8 Gansu 50 862 215.8 6211 26.3 1879 8.0 6.3:1 70.5 23.2 Ningxia 9977 193.9 935 18.2 256 5.0 8.4:1 26.8 21.5 Xinjiang 48 727 303.5 7260 45.2 2743 17.1 4.9:1 118.6 27.4 All provinces 1 115 843 204.0 144 433 26.4 42 805 7.8 6.0:1 – 22.9 Source: IEDC project a Number per 100 000 people. b Average notification rate in counties ranked among the top 10% according to the notification rate of new smear-positive cases during the fifth and sixth years of DOTS implementation. c Includes data from Chongqing municipality. 434 Bulletin of the World Health Organization 2002, 80 (6) Special Theme – Tuberculosis According to health regulations in China, hospitals are supposed to refer TB suspects and patients to the TB dispensary after they are identified. But there is an economic incentive for the hospitals to keep and treat TB suspects and patients, because they could charge patients for their TB- related diagnosis and treatment. The patientsmay also prefer to be treated by the hospitals, which are frequently perceived to have more clinical expertise than the TB dispensaries. Therefore, in spite of a regulation to refer patients, and that providers were paid a TB case-referral fee by the project, the degree of case referral was inadequate in most provinces. If TB patients were properly referred to the dispensary for treatment, the percentage of previously treated cases should be low. In Hong Kong, where DOTS is used and around 80% of all TB patients receive their treatment in the system of TB clinics, the percentage of previously treated cases is less than 10% (8). More research is needed to identify the incentives, approaches, or institutional arrangements that can best ensure that all TB patients are treated by a DOTS programme, regardless of where they are diagnosed. Probable reduction in level of drug-resistance The fourth lesson from this project is that DOTS can effectively reduce the number of previously treated cases in the community. Because a high percentage of these cases were chronically infectious and harboured drug-resistant organisms (9), reducing the community burden of these cases would have significant public health benefits. The notification rate of previously treated cases was high at the start of DOTS implementation, but decreased rapidly with the implementa- tion of DOTS. This was probably due to a reduction in the number of inadequately treated cases. The availability of free diagnosis and treatment in the DOTS programme reduced the proportion of patients treated by the hospital system and thus reduced the number of inadequately treated cases generated by the hospital system. At the same time, a high cure rate among new smear-positive cases in the DOTS programme reduced the number of treatment failures or defaulters, which again reduced the number of inadequately treated cases. The rapid decline in the notification rate of retreatment cases between the first and second year of DOTS implementa- tion suggested that there may have been a high prevalence of inadequately treated and chronic infectious cases in the community prior to the start of DOTS. Fortunately, the DOTS programme in China cured more than 80% of these cases. By reducing the number of prevalent or incident cases that are inadequately treated, the level of drug-resistant TB in the community can be reduced. This lesson is important for China as it seeks to control the problem of drug-resistant TB. In recently published reports, China had the highest number of multidrug-resistant (MDR) TB cases in the world and two provinces not involved in this DOTS project — Henan and Zhejiang — had some of the highest rates of MDR-TB in the world (9, 10). However, provinces involved in this project had lower rates of MDR-TB (9). These results further support our belief that DOTS can reduce the level of drug-resistant TB in the community. Even in areas where MDR-TB is endemic, DOTS may be able to reduce its incidence (11). Therefore, DOTS should be rapidly expanded to all areas in China as a matter of highest priority. Conclusion This 10-year experience with one-half of China’s population demonstrated the feasibility of rapid and large-scale DOTS expansion. Although the global target of an 85% cure rate for smear-positive cases was quickly achieved, the global target of a 70% case-detection rate was not achieved in the project due tomany limitations. This points to the challenge that China and many others countries will face, or are already facing, as DOTS programmes are scaled up globally. Nevertheless, the benefits of large-scale DOTS expansion for the individual patient and for society at large are obvious, as many thousands of patients were cured, deaths averted, and drug-resistance probably reduced because of this project (12). n Conflicts of interest: none declared. Re´sume´ La strate´gie DOTS en Chine : re´sultats et lec¸ons de dix ans d’expe´rience Objectif Analyser la strate´gie en cinq points de lutte contre la tuberculose (DOTS) dix ans apre`s sa mise en œuvre dans la moitie´ de la population chinoise, et indiquer les lec¸ons a` tirer de cette expe´rience en vue de futures applications. Me´thodes Nous avons analyse´ les tendances de la de´tection des cas et de l’issue du traitement apre`s la mise en œuvre de la strate´gie DOTS dans chaque district, en utilisant les donne´es de notification du projet IEDC de lutte contre les maladies infectieuses et ende´miques (1991-2000). Nous avons e´galement de´termine´ la proportion de districts posse´dant diffe´rents niveaux de de´tection des cas pour les cinquie`me et sixie`me anne´es de mise en œuvre du DOTS. Re´sultats De 1991 a` 1995, le DOTS a rapidement e´te´ e´tendu jusqu’a` couvrir plus de 90 % de la population et des districts cibles. 435Bulletin of the World Health Organization 2002, 80 (6) Ten years of DOTS in China En 2000, 8 millions de cas suspects ont be´ne´ficie´ d’un diagnostic gratuit : 1,8 million de cas de tuberculose ont e´te´ trouve´s, un traitement gratuit a e´te´ fourni a` 1,3 million de patients a` frottis positif et plus de 90 % d’entre eux ont e´te´ gue´ris. Pendant la pe´riode d’application du DOTS, le pourcentage de cas chez des sujets ayant de´ja` e´te´ traite´s a diminue´ parmi les cas a` frottis positif et l’issue du traitement s’est ame´liore´e. Malgre´ ces re´sultats, le taux de de´tection des nouveaux cas a` frottis positif n’a e´te´ que de 54 % en 1998, et dans 41,2 % des districts le taux de de´tection des cas e´tait faible ou infe´rieur a` la moyenne (avec d’importantes variations d’une province a` l’autre). Conclusion Le projet IEDC a de´montre´ qu’il est possible d’e´tendre rapidement le DOTS a` grande e´chelle. La cible globale consistant en un taux de gue´rison de 85 % a rapidement e´te´ atteinte, et le projet a probablement re´duit le taux de pharmacore´sistance. Toutefois, le taux de de´tection des cas n’a pas atteint la cible globale de 70 %, et il faudra poursuivre les recherches en vue d’ame´liorer ce re´sultat. Resumen La estrategia DOTS en China: resultados y lecciones al cabo de 10 an˜os Objetivo Analizar la estrategia de lucha contra la tuberculosis en cinco puntos, la denominada DOTS, 10 an˜os despue´s de empezar a aplicarla en la mitad de la poblacio´n de China, y apuntar lecciones para la futura aplicacio´n de dicha estrategia. Me´todos Analizamos las tendencias de la deteccio´n de casos y los resultados terape´uticos a lo largo del tiempo tras la aplicacio´n de la estrategia DOTS en cada distrito, empleando al efecto datos de notificacio´n sistema´tica procedentes del proyecto IEDC de Control de las Enfermedades Infecciosas y Ende´micas (1991–2000). Determinamos asimismo la proporcio´n de distritos con distintos niveles de deteccio´n de casos para los an˜os quinto y sexto de aplicacio´n de la DOTS. Resultados Entre 1991 y 1995 la DOTS amplio´ ra´pidamente su radio de accio´n hasta abarcar a ma´s del 90% de la poblacio´n y los distritos destinatarios. En 2000, 8 millones de casos sospechosos de tuberculosis habı´an sido objeto de una evaluacio´n diagno´stica gratuita, cuyo resultado fue la identificacio´n de 1,8 millones de casos de la enfermedad, el suministro de tratamiento gratuito a 1,3 millones de casos con frotis positivo, y una tasa de curacio´n de ma´s del 90%. Durante la aplicacio´n de la DOTS, el porcentaje de casos tratados anteriormente disminuyo´ entre todos los casos con frotis positivo, y los resultados terape´uticos mejoraron. Pese a esos logros, se estimo´ que la tasa de deteccio´n de casos nuevos con frotis positivo en el marco del proyecto fue de so´lo un 54% en 1998, y el 41,2% de los distritos presentaban un nivel de deteccio´n de casos bajo o inferior a la media (con diferencias sustanciales entre provincias). Conclusio´n El proyecto IEDC puso de manifiesto que es posible ampliar ra´pidamente la DOTS a gran escala. 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