Skip to main content
Advertisement
Browse Subject Areas
?

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here.

  • Loading metrics

Sequential Cross-Sectional Surveys in Orange Farm, a Township of South Africa, Revealed a Constant Low Voluntary Medical Male Circumcision Uptake among Adults despite Demand Creation Campaigns and High Acceptability

  • Esaie Marshall,

    Affiliations Institut National de la Santé et de la Recherche Médicale, Unit 1018, Centre for Research in Epidemiology and Population Health, Villejuif, France, Faculty of medicine, Research Unit 4184, Faculty of Medicine, University of Burgundy, Dijon, France

  • Reathe Rain-Taljaard,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Motlalepule Tsepe,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Cornelius Monkwe,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Florence Hlatswayo,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Simphiwe Tshabalala,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Simphiwe Khela,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Lindo Xulu,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Dumazile Xaba,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Tebogo Molomo,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Thobile Malinga,

    Affiliation Progressus Research and Development, Johannesburg, South Africa

  • Adrian Puren,

    Affiliations National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

  • Bertran Auvert

    bertran.auvert@uvsq.fr

    Affiliations Institut National de la Santé et de la Recherche Médicale, Unit 1018, Centre for Research in Epidemiology and Population Health, Villejuif, France, Assistance Publique—Hôpitaux de Paris, Hôpital Ambroise Paré, Boulogne-Billancourt, France, Faculty of Medicine, University of Versailles-Saint Quentin, Versailles, France

Abstract

Background

WHO recommends a male circumcision (MC) prevalence rate higher than 80% to have a substantial impact on the HIV-AIDS epidemic in Eastern and Southern Africa. Orange Farm, a township in South Africa, has a free-for-service voluntary medical male circumcision (VMMC) clinic in operation since 2008. Following an intense campaign from 2008 to 2010, MC prevalence rate increased to 55.4% (ANRS-12126). Ongoing and past VMMC campaigns focused on youths, through school talks, and adults at a community level. The main objective of the study was to assess the change in MC prevalence rate among adults aged 18–19 and 18–49 years in the past 5 years.

Methods

A cross-sectional survey (ANRS-12285) was conducted among a random sample of 522 adult men in 2015. MC status and characteristics of participants were collected through a genital examination and a face-to-face questionnaire.

Results

MC prevalence rate among young adult men aged 18–19 years increased markedly from 61.2% (95%CI: 57.4% to 65.0%) in 2010 to 87.5% (76.0% to 94.6%) in 2015 (p<0.001). In the same period, among men aged 18–49 years, MC prevalence rate varied slightly from 55.4% (53.6% to 57.1%) to 56.7% (52.4% to 60.9%). In 2015, 84.9% (79.2% to 89.5%) of uncircumcised adult men reported that they were willing to be circumcised. However, we estimated that only 4.6% (11/237; 2.5% to 7.9%) of the uncircumcised men underwent circumcision in 2015, despite 117/185 (63.2%; 95%CI: 56.1% to 69.9%) who reported that they were definitely willing to become circumcised.

Conclusions

In Orange Farm, VMMC campaigns were successful among the youth and led to a sufficiently high MC prevalence rate to have a substantial impact in the future on the HIV-AIDS epidemic. However, despite high acceptability and a free VMMC service, VMMC campaigns since 2010 have failed to increase MC prevalence rate among adults to above 80%. These campaigns should be revisited.

Introduction

Three randomized controlled trials have shown that male circumcision (MC) reduces the risk of heterosexual transmission of HIV infection to men by approximately 60% [13]. Following these trials, WHO and UNAIDS recommended in 2007 the use of voluntary medical male circumcision (VMMC) to fight the HIV-AIDS epidemic in countries with a low MC prevalence rate and a high HIV prevalence rate [4], conditions which correspond to most of the countries of Eastern and Southern Africa. A MC prevalence rate of 80% was recommended by WHO and UNAIDS as the target required to have a substantial impact on the HIV-AIDS epidemic [5].

Following the WHO and UNAIDS recommendation, a list of 14 priority countries in Africa was established and the rollout of VMMC was implemented, funded in the most part by PEPFAR. Over time, the MC prevalence in these countries increased, but coverage, which is the MC prevalence rate, varies substantially between countries. As of December 2014, while Ethiopia, Kenya and Tanzania have already reached 80% coverage targets, Lesotho, Malawi, Namibia, Rwanda and Zimbabwe have low coverage, ranging from 6% to 26% [6]. It is uncertain whether an 80% MC prevalence rate will be reached in all the priorities countries.

The township of Orange Farm, located in South Africa, one of the priority countries, has been a pioneer in VMMC. It was the study area where the first randomized controlled circumcision trial (ANRS-1265) was conducted and, to the best of our knowledge, where the first VMMC rollout (ANRS-12126) was implemented in the period 2008–2010. This rollout led to an increase in the adult MC prevalence rate from 12% in 2008 to 53% in 2011 [7]. Since 2010, and similar to many other places in Africa, routine VMMC demand creation has been organized, through school talks, advertisements and periodic door-to-door distribution of fliers. The main objective of this study was to assess the changes in MC prevalence rate in the past 5 years among men aged 18–49 years and to assess whether an 80% coverage rate had been reached. The secondary objectives were to identify demographic characteristics of uncircumcised men, determine knowledge and attitudes associated with MC, and to estimate the annual uptake of MC in the community.

Methods

Study setting

This study was conducted in the township of Orange Farm, in which the adult population is estimated to be 110,000 residents. The township is located approximately 40km from Johannesburg, in the Gauteng province. The province has experienced one of the most severe HIV epidemics in the world, with HIV prevalence estimated at 30% among antenatal women in 2011 [8]. In this township, a clinic offering free-for-service VMMC has been operating since 2008. It accepts males from the age of 10 years old.

Surveys

A cross-sectional biomedical survey (ANRS-12285) was conducted among a random sample of men between August and September 2015. A first random sample of 34 clusters was obtained among the 346 clusters obtained from Statistics South Africa Enumerator Area aerial photographs. In each of the 34 clusters, a systematic sample of 1 in 5 of the households was selected [9]. Voluntary, written informed consent was obtained from men aged 18–49 years. All men who stayed at least 2 nights in the household in the past 7 days and who spoke English or one of the 2 main local languages (Sesotho and IsiZulu) were eligible. Each participant was interviewed at home using an anonymous, structured and standardized questionnaire. Interviews were followed by individual and confidential HIV and STI counselling and testing. Participants underwent a clinical examination performed by a trained male nurse to assess their clinical MC status (presence or absence of foreskin). Participants with symptomatic STIs were treated free of charge at the study site or at local health facilities according to the national STI syndromic management treatment guidelines. Individuals who tested positive for HIV were referred for appropriate care and treatment. Among 981 eligible households, 870 accepted to participate in the study, which corresponds to a response rate of 88.5%. In these 870 households, 696 men were eligible and 522 men accepted to participate in the study, which corresponds to a response rate of 75.0%.

During the survey, the following background characteristics were collected; age group, ethnic group, religion, alcohol consumption, education level, occupation, current and previous marital status, parenthood status, monthly income and length of stay in Orange Farm. Other collected factors were HIV testing history and self-assessment of HIV infection risk level. Factors related to knowledge and attitude regarding MC were also collected. For men reporting themselves as uncircumcised, willingness to become circumcised and the main reason for not being circumcised were collected. For circumcised men, we collected the main reason for being circumcised and the date of circumcision. We observed that some men made false claims of being circumcised. As a result and because the collection of data preceded the genital examination, these men were excluded from the data collected specifically from uncircumcised men (willingness to become circumcised and main reason for being uncircumcised).

The Human Research Ethics Committee (Medical) of the University of the Witwatersand, Johannesburg, South Africa, granted ethical clearance for the study on January 19th 2015 (M140946).

Statistical analysis

The main outcome of this study was the MC status observed by the nurse during the genital examination. Analyses were conducted among the whole sample, and among the circumcised and uncircumcised men. We analyzed the association of background characteristics with MC status by estimating prevalence rate ratios (PRR) and adjusted PRR (aPRR) using univariate and multivariate general linear models (Poisson regression). We used the binomial test to compare observed male circumcision prevalence rates with the value of 80%. 95%CI of proportions were calculated using the Clopper-Pearson interval by calculating quantiles from the beta distribution [10]. A sample size of 1000 households was judged as sufficient to obtain a sample of at least 500 men. Analyses were computed using the R statistical package [11].

Results

Characteristics of survey participants

Among the 522 men taking part in the survey, the mean age (median; interquartile range) was 30.5 years (28.9; 23.0 to 37.1). The prevalence rate of MC was 296/522 (56.7%; 95%CI: 52.4% to 60.9%), which is significantly different from 80% (p<0.001).

Table 1 indicates the background characteristics of the sample. Approximately 75% of the participants reported being residents of Orange Farm for five years or longer. The Sesotho and IsiZulu ethnic groups each represent one third of the population. More than half of the participants reported to be employed and half of the participants left school without having completed the 12th grade.

thumbnail
Table 1. Background characteristics of the sample surveyed in 2015 and association with male circumcision status.

https://doi.org/10.1371/journal.pone.0158675.t001

Table 2 indicates the other characteristics of the participants. Approximately 75% of uncircumcised men knew about free-of-charge circumcision in Orange Farm. The majority of the participants had good knowledge regarding MC and preferred to have their male children circumcised. For example, nearly all men reported that a circumcised man can become infected with HIV and that a woman having unprotected sex with a circumcised man is not protected against HIV infection.

thumbnail
Table 2. Characteristics related to HIV and male circumcision of the sample surveyed in 2015 and association with male circumcision status.

https://doi.org/10.1371/journal.pone.0158675.t002

MC prevalence rate over time

Fig 1 represents the variation with time of the MC prevalence rate among adults aged 18 to 49 years. This prevalence rate increased only very slightly between 2010–2011 and 2015, from 55.4 to 56.7% (p = 0.60). However, when controlling for age group, we found an aPRR of 1.15 (95%CI: 1.05 to 1.25) p = 0.002. Knowing that the time since the 2010–2011 survey was 4.5 years, this aPRR corresponds to an average increase per year of 3.1% (95%CI: 1.2% to 8.6%).

thumbnail
Fig 1. Male circumcision (MC) prevalence rate among men aged 18–49 years obtained in three independent cross-sectional surveys conducted in Orange Farm in the years 2007–2008, 2010–2011 and 2015.

https://doi.org/10.1371/journal.pone.0158675.g001

Fig 2 represents the variation with time of the MC prevalence rate among adults aged 18 to 19 years. This prevalence rate increased from 9.5% in 2007–2008 to 87.5% (42/48; 95%CI: 76.0% to 94.6%) in 2015, a value not significantly different from 80% (p = 0.28).

thumbnail
Fig 2. Male circumcision (MC) prevalence rate among men aged 18–19 years obtained in three independent cross-sectional surveys conducted in Orange Farm in the years 2007–2008, 2010–2011 and 2015.

https://doi.org/10.1371/journal.pone.0158675.g002

Among adults aged 20 to 29 years the MC prevalence increased from 56.9% (1146/2013) to 61.8% (144/233) between 2010–2011 and 2015, which corresponds to an aPRR adjusted on age group of 1.10 (0.98–1.23) p = 0.10.

Among the circumcised men, 11 reported to have been circumcised in the past 12 months. The proportion of circumcised men among those who were uncircumcised 12 months ago was estimated as 11/(226+11), corresponding to an uptake rate of 4.6% (95%CI: 2.5% to 7.9%) per year.

Reported MC status

Among the 337 men who reported to be circumcised, 41 (12.2%; 95%CI: 9.0% to 16.0%) were in fact uncircumcised. Among the 185 men who reported to be uncircumcised 0 (95%CI: 0.0% to 1.3%) were in fact circumcised. To report having attended an initiation school was not a good marker of the MC status as 88/131 (67.2%; (95%CI: 58.8% to 74.8%) were circumcised, while the number of circumcised men among those reporting to not have attended an initiation school was 208/391 or 53.2% (95%CI: 48.2% to 58.1%).

Characteristics of uncircumcised men

As shown in Table 1, in comparison with circumcised men, uncircumcised men were older, more often Zulu in ethnic origin, less educated and more often recently resident in Orange Farm. The multivariate analysis indicated in Table 2 shows that among uncircumcised men, in comparison with circumcised men, the proportion having ever been tested for HIV was 42% lower, the proportion reporting being at risk of HIV infection was 17% higher, the proportion reporting that MC increases pleasure during sex was 43% lower, the proportion reporting that circumcised men do not need to use condoms to protect them from HIV was also 36% lower, and the proportion reporting that circumcised men can become infected with HIV was 30% lower.

Table 3 summarizes the main reasons reported by uncircumcised men for not being circumcised. 65.4% of the reasons were accounted for by the following responses: "It is not my culture", "Fear of the procedure, fear of pain or injury", and "I do not have the time".

thumbnail
Table 3. Main reason given by uncircumcised men for not being circumcised.

https://doi.org/10.1371/journal.pone.0158675.t003

Among the 185 uncircumcised men, 117 (63.2%; 95%CI: 56.1% to 69.9%) reported that they were "Definitely" willing to become circumcised in the future, and 40 (21.6%; 95%CI: 16.2% to 28.0%) said "Maybe". As a result, a total of 157/185 84.9%; 95%CI: 79.2% to 89.5%) were not opposed to undergoing circumcision. Six uncircumcised men reported that they were "Unlikely" (3.2%; 95%CI: 1.4% to 6.6%) and 22 reported as being "Definitively not" (11.9%; 95%CI: 7.8% to 17.1%) willing to undergo circumcision in the future. Among those 28 men not willing to undergo circumcision, 15 reported that their culture or religion was the main reason for not being circumcised (53.6%; 95%CI: 35.5% to 70.9%).

Main reason for being circumcised

The main reasons for being circumcised are given in Table 4. Approximately 63% of the participants reported the three following main reasons "To reduce the risk of getting HIV", "Because of tradition or religion" and "Hygiene".

thumbnail
Table 4. Main reason given by circumcised men for being circumcised.

https://doi.org/10.1371/journal.pone.0158675.t004

Discussion

Main results

Using sequential, independent and random cross-sectional surveys conducted over a period of 7.5 years in the township of Orange Farm, we observed that the prevalence rate of MC among adults aged 18–49 remained almost stable between 2010–2011 and 2015. However, the late adolescent MC prevalence rate among men aged 18–19 years was just over 80%. The vast majority of the uncircumcised adults reported that they would be willing to undergo circumcision.

Trends over time

In Orange Farm, an 80% MC coverage has already been achieved among young adults. This high coverage among young adults likely results from the intense campaigns among schools that was started with the Bophelo Pele project in 2008 [12] and repeated each year. The campaigns have led to a change of social norms regarding MC among the youth. To sustain the high coverage of MC among the youth, school talks and the free VMMC clinic in Orange Farm must be maintained. The reason for this success among the youth may be the fact that MC is now culturally and socially more acceptable for the youth than for adults [13,14].

A consequence of the high MC prevalence rate among the youth is that MC prevalence rate is expected to increase among adults with the replacement of generations. This increase will, however, take time. Our study showed that the increase among adults is unlikely to be expected from the current VMMC demand creation in Orange Farm, as the MC prevalence rate has remained relatively stable since 2011. The current demand creation is less intensive than the initial implementation during the 2008–2010 period. For example, between 2008 and 2010 thirty-six field workers were recruiting men for VMMC in Orange Farm. After 2010 this was reduced to two or three.

The results obtained in Orange Farm cannot be immediately extrapolated to other settings. Orange Farm is, however, considered as having similar characteristics to other townships in South Africa. The fact that MC prevalence rate is stable among adults despite the history of VMMC, some ongoing VMMC demand creation activities and the presence of a free-for-service VMMC clinic in the township is not reassuring. Coverage of 80% among adults may be difficult to obtain in South Africa.

In order to obtain MC coverage of 80% in the 14 priority countries, 20.8 million VMMCs will have to be performed [5]. To have reached the target mid-point of 10.4 million MCs is a remarkable success [15] obtained mainly thanks to PEPFAR funding but also due to political investment in these countries. 80% MC coverage has already been obtained in Ethiopia, Kenya and Tanzania. The experience in Orange Farm draws attention to the challenges in achieving the required coverage of 80% in some settings.

Barriers to MC program success

The important factors associated with being uncircumcised were age and ethnic group. Such factors have already been found to be important in other studies conducted in Eastern and Southern African countries where MC prevalence was low in the 2000s [1620]. As also found in several other studies, the main reported reasons for not being circumcised were related to culture and fear of pain. Reasons that may be relatively easily addressed are fear of pain and lack of time, which represented almost 36% of the reasons mentioned by the participants [16,18,19,21].

Limitations

We acknowledge that our study has two limitations that need to be considered. Firstly, the response rate among participants was approximately 75%. The fieldworkers reported that about half of the reasons given for refusing to participate in the survey were related to the necessity to have a genital examination. The potential bias could not be assessed because no data were collected among those who refused to participate in the survey. Such a response rate is common among cross-sectional surveys. Secondly, we observed that 12% of men made false claims of being circumcised. As a result, and described in the Methods section, the analyses of the willingness to become circumcised and the main reason for being uncircumcised were conducted among 185 men only instead of 226.

Conclusion

Our study showed that uncircumcised men have accurate knowledge about MC, which shows that convincing uncircumcised men to become circumcised is not a question of diffusing knowledge. To obtain coverage of 80% from the current MC prevalence rate of 56%, approximately 55% (24/100-56) of uncircumcised men must be convinced to undergo circumcision. This should be feasible as our study showed that 63% of uncircumcised men reported that they were "definitely" willing to become circumcised. However, it is unlikely that the current methods of demand creation used to encourage circumcision will be successful in achieving the 80% coverage among adult males in the near future. Indeed, as shown in this study, approximately 75% of the uncircumcised men interviewed for this survey in Orange Farm had lived in this community for more than 5 years, and thus were exposed to the intense campaign of 2008–2010 and the subsequent campaigns from 2011. In this context, the current VMMC campaigns among adults in Orange Farm should be revisited and new approaches devised and tested to convince uncircumcised men to undergo circumcision. Among these new possible approaches, motivational talks and financial incentives should be considered [2224].

Acknowledgments

The authors would like to thank Agenda Gumbo from Progressus (South Africa) for his contribution to this study.

Author Contributions

Conceived and designed the experiments: BA RRT. Performed the experiments: RRT MT CM FH ST LX DX TM SK. Analyzed the data: EM BA. Wrote the paper: EM BA AP RRT.

References

  1. 1. Auvert B, Taljaard D, Lagarde E, Sobngwi-Tambekou J, Sitta R, Puren A. Randomized, controlled intervention trial of male circumcision for reduction of HIV infection risk: the ANRS 1265 Trial. PLoS Med. 2005;2: e298. pmid:16231970
  2. 2. Bailey RC, Moses S, Parker CB, Agot K, Maclean I, Krieger JN, et al. Male circumcision for HIV prevention in young men in Kisumu, Kenya: a randomised controlled trial. Lancet. 2007;369: 643–56. pmid:17321310
  3. 3. Gray RH, Kigozi G, Serwadda D, Makumbi F, Watya S, Nalugoda F, et al. Male circumcision for HIV prevention in men in Rakai, Uganda: a randomised trial. Lancet. 2007;369: 657–66. pmid:17321311
  4. 4. WHO-UNAIDS. Technical Consultation on Male Circumcision and HIV Prevention: Research Implications for Policy and Programming. New Data Male Circumcision HIV Prev Policy Programme Implic. 2007; Available: http://www.who.int/hiv/mediacentre/MCrecommendations_en.pdf
  5. 5. WHO-UNAIDS. Joint Strategic Action Framework to Accelerate the Scale-Up of Voluntary Medical Male Circumcision for HIV Prevention in Eastern and Southern Africa 2012–2016 [Internet]. Geneva; 2011. Available: http://www.who.int/hiv/pub/strategic_action2012_2016/en/
  6. 6. WHO-UNAIDS. UNAIDS World AIDS day report [Internet]. Geneva; 2015. Available: http://www.unaids.org/sites/default/files/media_asset/WAD2015_report_en_part01.pdf
  7. 7. Auvert B, Taljaard D, Rech D, Lissouba P, Singh B, Bouscaillou J, et al. Association of the ANRS-12126 male circumcision project with HIV levels among men in a South African township: evaluation of effectiveness using cross-sectional surveys. PLoS Med. 2013;10: e1001509. pmid:24019763
  8. 8. National Department of Health P. The 2010 National antenatal sentinel HIV and syphilis prevalence survey in South Africa. 2011 pp. 50–53.
  9. 9. Vaughan Liwen. Statistical Methods for the Information Professional. Second edition. New jersy, USA: Information Today, Inc; 2003.
  10. 10. Clopper C, Pearson ES. The use of confidence or fiducial limits illustrated in the case of the binomial. Biometrika. 1934;26: 404–413.
  11. 11. R Development Core Team. R: a language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria; 2005.
  12. 12. Lissouba P, Taljaard D, Rech D, Doyle S, Shabangu D, Nhlapo C, et al. A model for the roll-out of comprehensive adult male circumcision services in African low-income settings of high HIV incidence: the ANRS 12126 Bophelo Pele Project. PLoS Med. 2010;7: e1000309. pmid:20652013
  13. 13. Mahler HR, Kileo B, Curran K, Plotkin M, Adamu T, Hellar A, et al. Voluntary Medical Male Circumcision: Matching Demand and Supply with Quality and Efficiency in a High-Volume Campaign in Iringa Region, Tanzania. Sansom SL, editor. PLoS Med. 2011;8: e1001131. pmid:22140366
  14. 14. Westercamp N, Bailey RC. Acceptability of Male Circumcision for Prevention of HIV/AIDS in Sub-Saharan Africa: A Review. AIDS Behav. 2007;11: 341–355. pmid:17053855
  15. 15. WHO-UNAIDS. Voluntary medical male circumcision for HIV prevention in 14 priority African countries in East and Southern Africa. [Internet]. Geneva; 2015. Report No.: WHO / HIV/2015.21. Available: http://apps.who.int/iris/bitstream/10665/179933/1/WHO_HIV_2015.21_eng.pdf?ua=1&ua=1
  16. 16. Kong X, Ssekasanvu J, Kigozi G, Lutalo T, Nalugoda F, Serwadda D, et al. Male circumcision coverage, knowledge, and attitudes after 4-years of program scale-up in Rakai, Uganda. AIDS Behav. 2014;18: 880–884. pmid:24633740
  17. 17. Ssekubugu R, Leontsini E, Wawer MJ, Serwadda D, Kigozi G, Kennedy CE, et al. Contextual Barriers and Motivators to Adult Male Medical Circumcision in Rakai, Uganda. Qual Health Res. 2013;23: 795–804. pmid:23515302
  18. 18. Hatzold K, Mavhu W, Jasi P, Chatora K, Cowan FM, Taruberekera N, et al. Barriers and Motivators to Voluntary Medical Male Circumcision Uptake among Different Age Groups of Men in Zimbabwe: Results from a Mixed Methods Study. Tang JW, editor. PLoS ONE. 2014;9: e85051. pmid:24802746
  19. 19. Westercamp N, Bailey RC. Acceptability of Male Circumcision for Prevention of HIV/AIDS in Sub-Saharan Africa: A Review. AIDS Behav. 2006;
  20. 20. Herman-Roloff A, Llewellyn E, Obiero W, Agot K, Ndinya-Achola J, Muraguri N, et al. Implementing Voluntary Medical Male Circumcision for HIV Prevention in Nyanza Province, Kenya: Lessons Learned during the First Year. Gray R, editor. PLoS ONE. 2011;6: e18299. pmid:21483697
  21. 21. Jones D, Cook R, Arheart K, Redding CA, Zulu R, Castro J, et al. Acceptability, Knowledge, Beliefs, and Partners as Determinants of Zambian Men’s Readiness to Undergo Medical Male Circumcision. AIDS Behav. 2014;18: 278–284. pmid:23757123
  22. 22. Thirumurthy H, Masters SH, Rao S, Bronson MA, Lanham M, Omanga E, et al. Effect of providing conditional economic compensation on uptake of voluntary medical male circumcision in Kenya: a randomized clinical trial. JAMA. 2014;312: 703–711. pmid:25042290
  23. 23. Lundahl B, Burke BL. The effectiveness and applicability of motivational interviewing: a practice-friendly review of four meta-analyses. J Clin Psychol. 2009;65: 1232–1245. pmid:19739205
  24. 24. Miller WR, Rose GS. Toward a theory of motivational interviewing. Am Psychol. 2009;64: 527–537. pmid:19739882