As indicated in the PRISMA flow diagram of studies in Figure , 3470 records were identified through database searching for a total 1892 unique citations. All citations were screened for inclusion by two authors, using study selection criteria outlined above. Through this process, a total of 105 studies were selected for full text review. Of the 105 abstracts, 37 studies were included in this review (see Tables , and ). Thirteen studies targeted breast cancer screening only, fifteen targeted cervical cancer screening only, and nine focused on both breast cancer and cervical cancer screening. Of these 37 intervention studies, 18 were situated in the US (48.6%); 5 in Taiwan (13.5%), 3 in Thailand (8.1%), 3 in the UK (8.1%), 1 in Canada (2.7%), 1 in Singapore (2.7%), 1 in Australia/Thailand (2.7%), 1 in New Zealand (2.7%), 1 in Hong Kong (2.7%), 1 in India (2.7%), 1 in Malaysia (2.7%), and 1 in the US and Canada (2.7%). The target populations of these interventions included Asian immigrants or women living in their home countries in Asia. The intervention population sample size ranges from 72 to 29,073. Out of the 37 selected intervention studies, 28 (75.7%) were implemented and evaluated within a one to two year period; 6 (16.2%) within a three to five year period; and only 2 (5.4%) with a seven or eight year period.
Breast cancer screening intervention studies on Asian women
Cervical cancer screening intervention studies on Asian women
Breast and cervical cancer screening intervention studies on Asian women
The included studies are extremely diverse in terms of the intervention strategies that were adopted. Most studies used multiple strategies. As described in Table , intervention strategies to enhance breast cancer screening included those targeting both patients and health care professionals. Interventions targeting patients included two types: individual-based interventions, including culturally sensitive print or audiovisual materials, home education visits, screening reminders/invitations (letters), case management, mobile screening services, free/subsidized screening services; and, group based interventions including community based, workplace based, church based, grocery store based group education, and media campaigns. Interventions that targeted health care professionals included cultural awareness training and screening education for health care professionals. As described in Table , Intervention strategies to enhance cervical cancer screening included assistance in scheduling/attending screening and screening reminders/invitations (telephone calls). Studies presented in Table were aimed at enhancing both breast cancer and cervical cancer screening uptake and reflect the most complete set of cancer screening intervention strategies adopted in practice. In addition to the strategies listed above, strategies aimed at increasing both breast and cervical cancer screening also included screening follow-up, financial incentives, free/subsidized screening services, female physicians, free transportation, and the availability of interpreters.
Only eighteen of the included studies (see Table ) reported effectiveness based on completion of mammograms or Pap smear, either by self-report and/or verified through clinical record. Of the studies reporting these outcome measures, 8 are randomized control trials (including cluster randomized and randomized controlled crossover trials); 9 are non-equivalent control group designs, and 1 is a prospective cohort study. As reported in Table , the Jadad scores of the RCTs are either 2 or 3, indicating that the RCTs included in this review, while not low quality, cannot be classified as being of the highest quality and are therefore subject to some degree of bias.
Breast and cervical cancer intervention studies: evidence on effectiveness
Quality Assessment of Randomized Controlled Trials (using Jadad assessment criteria)
Given that eleven of the eighteen selected studies used multiple and highly diversified intervention strategies, it is impossible to identify or estimate the actual effectiveness of any specific intervention strategy. Instead, we examined whether there were evidences to support the overall effectiveness of the intervention programs, and reported the results by each intervention strategy instead of by individual intervention. It should be highlighted that we could not arrive at a conclusive and generalizable conclusion on effectiveness of any one particular intervention.
A 2006 study found no significant evidence to support the effectiveness of home visits by researchers providing culturally-sensitive health education emphasizing the need for Pap smear screening, and inviting Thai women in Khon Kaen, Thailand to participate in Pap smear testing [43
]. Similarly, home visits were not found to be effective among Pakistani and Bangladeshi women in Oldham, UK [41
]. However, personal visits (with video or leaflets) were found to be more effective than sending written translated materials by post to enhance cervical cancer screening among Indian, Pakistani, Bangladeshi women in Leicester, New Zealand [60
]. In the Singapore 1994–1996 study [39
], home visits to deliver routine second-reminder letters and health educational booklets were found to be more effective than mailing routine reminders and/or health education booklets (13.3% vs. 7.6%, 95% CI 1.19 to 2.59).
A media-led culturally sensitive education campaign was not found to be effective among Vietnamese Americans in California [70
]. A county-wide neighborhood-based intervention involving education, media campaigns and screening education for Vietnamese physicians, was also found to be ineffective in increasing screening rates [37
Mailed culturally sensitive print materials
Mailed translated education materials were not found to be effective among Indian, Pakistani, Bangladeshi women in Leicester, New Zealand [60
]. Comparing the effectiveness of direct-mail cervical cancer screening campaigns followed by a phone counseling intervention versus newsletter alone, Hou and colleagues found that interventions targeting individuals through direct mail and phone counseling were more effective than a monthly newsletter intervention (50% vs. 32%, p
]. Seouw and colleagues found that providing health education booklets did not increase uptake above what could have been achieved through routine letter reminders [60
Community- or work-based education
Small group discussions with health professionals were not found to be effective in increasing cancer screening among Filipino Americans in Los Angeles [62
]. In the “Tell a Friend” Alameda 1994–2002 study, a wide-range of community-based interventions were not shown to be effective in enhancing breast or cervical cancer screening among Korean Americans at the community level [66
]. In the Lay Health Workers Outreach 1992–1996 study, media campaigns and the distribution of culturally sensitive print materials, was supplemented by community-based small group sessions delivered by lay health workers [69
]. Both mammography and Pap smear screening rates increased significantly among the Vietnamese Americans in the intervention group. In the Pennsylvania 2004 study, Korean American women in the intervention group received cervical cancer education and patient navigation services from bilingual Korean health educators. There was a significant increase in actual cervical cancer screening rates among this group compared with the control group (82.7% vs. 22.0%, p
0.001). A combination of assistance in scheduling/attending screening, community based group education, and culturally sensitive audiovisual materials increased screening rates among Korean-American women [45
]. A workplace-based group-teaching program in Taiwan focused on married women’s knowledge, health beliefs and behavior regarding cervical cancer screening was shown to be more effective than a pamphlet by mail intervention (90.9% vs. 77.5%, p
Lay health worker outreach
The Lay Health-Worker Outreach 2001–2004 study found that combining lay health worker outreach with a media education campaign was more effective than a media education campaign alone to promote mammography screening among Vietnamese Americans [49
]. Taylor and colleagues found outreach interventions, which involved tailored counseling, and logistic assistance during home visits by trilingual, bicultural outreach workers was cost effective compared with direct mail (cost per additional woman obtaining a Pap test $304.42 vs. $485.40) [52
]. In the Seattle 2000–2001 study, Cambodian American women in the intervention group received home visits by outreach workers and were invited to group meetings in neighborhood settings. The study found similar increase in reported Pap test rates in both intervention and control groups. Although no evidence was found to support the effectiveness of home visits by outreach workers, the reported findings might be a result of spillover effect from the target group to the entire community [72
Mobile screening services
The Let’s Talk between Women study compared peer-group education programs, in addition to low-cost mammography with providing access to low-cost mammography alone. The peer-group education program did not increase screening as compared with providing low-cost mobile mammography [26
]. In the Los Angeles 1998–2000 study, an intervention involving an on-site multi-component education program and mobile mammography at community-based sites where older women gathered was compared with health education. The results suggested that the combination of on-site mobile mammography and health education was more effective than health education alone (70% vs. 35%, p
Cultural awareness training for health care professionals
In the Newham 1995 study [38
], a two-hour cultural awareness training program was provided to general practice reception staff. It resulted in a significant increase in mammogram screening attendance among Asian women as compared with the control group (9% vs. 4%, p