This strategy will be implemented for 18 months at half of the clinics within the contact tracing arm (n=14) and, after a six-month washout period, for 18 months in the other half of the clinics in that arm (n = 14). All adults (and guardians for children) with newly diagnosed pulmonary TB will be approached for enrolment as described above. Consenting patients (estimated as 1,575 subjects) will be asked for a home address (with landmarks), mobile phone number, and convenient time for a household visit. A mobile field team consisting of a nurse and lay health worker (both research staff) will circulate between the 14 primary care clinics, with notifications of all new TB cases made from the clinic to the team by mobile phone. The field team will visit the household of each consenting index case within two weeks of notification; each visit will consist of a household census (including demographic data), consent of all eligible household members for questioning and TB screening, administration of a brief questionnaire (including symptomatology, self-reported HIV and TB history, care-seeking behavior, and acceptability of the intervention), and sputum collection for testing with Xpert MTB/RIF. Each participant will also be offered voluntary HIV counselling and testing. The team will make up to three visits to each household as needed in order to approach all household contacts for study enrolment.

This strategy will be implemented in the opposite half of the clinics randomized to contact investigation. All adults (and guardians of children) with newly diagnosed active TB will be identified and approached for enrolment as described above. However, rather than a household visit, each consenting individual will be provided with a set of 10 coupons to give to household members and close contacts whom the index case believes may be at greatest risk. These coupons will contain instructions on how to come to the clinic for free TB screening (e.g., when the study team will be at each clinic), and will have an expiration date of 2 months from the time of initial TB diagnosis. When a contact presents at the clinic with the coupon, the contact will receive a small amount of money and a transport allowance based on the distance travelled to the clinic. If the contact is diagnosed with active TB and starts treatment, the contact will receive an additional larger amount of money. Study staff will document which index case the contact is linked to, and whether the contact is diagnosed with active TB. At the end of the 2 month period in which the coupons are valid the index will receive a grocery voucher for the total incentive earned (e.g., total amount for contact(s) who presented for screening + total amount for contact(s) diagnosed with active TB and starting treatment).

The primary outcome of the study was the comparative number of people with incident TB diagnosed and started on treatment at study clinics during the two study periods, excluding the six-month washout period. The number of people starting treatment for incident TB was calculated by performing a review of paper and electronic medical records at each clinic on a quarterly basis during the study.

Adjusted for district, study phase and clinic random effect.

This strategy will be implemented for 18 months at half of the clinics within the contact tracing arm (n=14) and, after a six-month washout period, for 18 months in the other half of the clinics in that arm (n = 14). All adults (and guardians for children) with newly diagnosed pulmonary TB will be approached for enrolment as described above. Consenting patients (estimated as 1,575 subjects) will be asked for a home address (with landmarks), mobile phone number, and convenient time for a household visit. A mobile field team consisting of a nurse and lay health worker (both research staff) will circulate between the 14 primary care clinics, with notifications of all new TB cases made from the clinic to the team by mobile phone. The field team will visit the household of each consenting index case within two weeks of notification; each visit will consist of a household census (including demographic data), consent of all eligible household members for questioning and TB screening, administration of a brief questionnaire (including symptomatology, self-reported HIV and TB history, care-seeking behavior, and acceptability of the intervention), and sputum collection for testing with Xpert MTB/RIF. Each participant will also be offered voluntary HIV counselling and testing. The team will make up to three visits to each household as needed in order to approach all household contacts for study enrolment.

This strategy will be implemented in the opposite half of the clinics randomized to contact investigation. All adults (and guardians of children) with newly diagnosed active TB will be identified and approached for enrolment as described above. However, rather than a household visit, each consenting individual will be provided with a set of 10 coupons to give to household members and close contacts whom the index case believes may be at greatest risk. These coupons will contain instructions on how to come to the clinic for free TB screening (e.g., when the study team will be at each clinic), and will have an expiration date of 2 months from the time of initial TB diagnosis. When a contact presents at the clinic with the coupon, the contact will receive a small amount of money and a transport allowance based on the distance travelled to the clinic. If the contact is diagnosed with active TB and starts treatment, the contact will receive an additional larger amount of money. Study staff will document which index case the contact is linked to, and whether the contact is diagnosed with active TB. At the end of the 2 month period in which the coupons are valid the index will receive a grocery voucher for the total incentive earned (e.g., total amount for contact(s) who presented for screening + total amount for contact(s) diagnosed with active TB and starting treatment).

The pre-specified secondary study outcome was the number of Xpert-based TB diagnoses made among enrolled contacts ("secondary cases") by arm.

Adjusted for study phase and district

This strategy will be implemented for 18 months at half of the clinics within the contact tracing arm (n=14) and, after a six-month washout period, for 18 months in the other half of the clinics in that arm (n = 14). All adults (and guardians for children) with newly diagnosed pulmonary TB will be approached for enrolment as described above. Consenting patients (estimated as 1,575 subjects) will be asked for a home address (with landmarks), mobile phone number, and convenient time for a household visit. A mobile field team consisting of a nurse and lay health worker (both research staff) will circulate between the 14 primary care clinics, with notifications of all new TB cases made from the clinic to the team by mobile phone. The field team will visit the household of each consenting index case within two weeks of notification; each visit will consist of a household census (including demographic data), consent of all eligible household members for questioning and TB screening, administration of a brief questionnaire (including symptomatology, self-reported HIV and TB history, care-seeking behavior, and acceptability of the intervention), and sputum collection for testing with Xpert MTB/RIF. Each participant will also be offered voluntary HIV counselling and testing. The team will make up to three visits to each household as needed in order to approach all household contacts for study enrolment.

This strategy will be implemented in the opposite half of the clinics randomized to contact investigation. All adults (and guardians of children) with newly diagnosed active TB will be identified and approached for enrolment as described above. However, rather than a household visit, each consenting individual will be provided with a set of 10 coupons to give to household members and close contacts whom the index case believes may be at greatest risk. These coupons will contain instructions on how to come to the clinic for free TB screening (e.g., when the study team will be at each clinic), and will have an expiration date of 2 months from the time of initial TB diagnosis. When a contact presents at the clinic with the coupon, the contact will receive a small amount of money and a transport allowance based on the distance travelled to the clinic. If the contact is diagnosed with active TB and starts treatment, the contact will receive an additional larger amount of money. Study staff will document which index case the contact is linked to, and whether the contact is diagnosed with active TB. At the end of the 2 month period in which the coupons are valid the index will receive a grocery voucher for the total incentive earned (e.g., total amount for contact(s) who presented for screening + total amount for contact(s) diagnosed with active TB and starting treatment).

This strategy will be implemented for 18 months at half of the clinics within the contact tracing arm (n=14) and, after a six-month washout period, for 18 months in the other half of the clinics in that arm (n = 14). All adults (and guardians for children) with newly diagnosed pulmonary TB will be approached for enrolment as described above. Consenting patients (estimated as 1,575 subjects) will be asked for a home address (with landmarks), mobile phone number, and convenient time for a household visit. A mobile field team consisting of a nurse and lay health worker (both research staff) will circulate between the 14 primary care clinics, with notifications of all new TB cases made from the clinic to the team by mobile phone. The field team will visit the household of each consenting index case within two weeks of notification; each visit will consist of a household census (including demographic data), consent of all eligible household members for questioning and TB screening, administration of a brief questionnaire (including symptomatology, self-reported HIV and TB history, care-seeking behavior, and acceptability of the intervention), and sputum collection for testing with Xpert MTB/RIF. Each participant will also be offered voluntary HIV counselling and testing. The team will make up to three visits to each household as needed in order to approach all household contacts for study enrolment.

This strategy will be implemented in the opposite half of the clinics randomized to contact investigation. All adults (and guardians of children) with newly diagnosed active TB will be identified and approached for enrolment as described above. However, rather than a household visit, each consenting individual will be provided with a set of 10 coupons to give to household members and close contacts whom the index case believes may be at greatest risk. These coupons will contain instructions on how to come to the clinic for free TB screening (e.g., when the study team will be at each clinic), and will have an expiration date of 2 months from the time of initial TB diagnosis. When a contact presents at the clinic with the coupon, the contact will receive a small amount of money and a transport allowance based on the distance travelled to the clinic. If the contact is diagnosed with active TB and starts treatment, the contact will receive an additional larger amount of money. Study staff will document which index case the contact is linked to, and whether the contact is diagnosed with active TB. At the end of the 2 month period in which the coupons are valid the index will receive a grocery voucher for the total incentive earned (e.g., total amount for contact(s) who presented for screening + total amount for contact(s) diagnosed with active TB and starting treatment).

This strategy will be implemented for 18 months at half of the clinics within the contact tracing arm (n=14) and, after a six-month washout period, for 18 months in the other half of the clinics in that arm (n = 14). All adults (and guardians for children) with newly diagnosed pulmonary TB will be approached for enrolment as described above. Consenting patients (estimated as 1,575 subjects) will be asked for a home address (with landmarks), mobile phone number, and convenient time for a household visit. A mobile field team consisting of a nurse and lay health worker (both research staff) will circulate between the 14 primary care clinics, with notifications of all new TB cases made from the clinic to the team by mobile phone. The field team will visit the household of each consenting index case within two weeks of notification; each visit will consist of a household census (including demographic data), consent of all eligible household members for questioning and TB screening, administration of a brief questionnaire (including symptomatology, self-reported HIV and TB history, care-seeking behavior, and acceptability of the intervention), and sputum collection for testing with Xpert MTB/RIF. Each participant will also be offered voluntary HIV counselling and testing. The team will make up to three visits to each household as needed in order to approach all household contacts for study enrolment.

This strategy will be implemented in the opposite half of the clinics randomized to contact investigation. All adults (and guardians of children) with newly diagnosed active TB will be identified and approached for enrolment as described above. However, rather than a household visit, each consenting individual will be provided with a set of 10 coupons to give to household members and close contacts whom the index case believes may be at greatest risk. These coupons will contain instructions on how to come to the clinic for free TB screening (e.g., when the study team will be at each clinic), and will have an expiration date of 2 months from the time of initial TB diagnosis. When a contact presents at the clinic with the coupon, the contact will receive a small amount of money and a transport allowance based on the distance travelled to the clinic. If the contact is diagnosed with active TB and starts treatment, the contact will receive an additional larger amount of money. Study staff will document which index case the contact is linked to, and whether the contact is diagnosed with active TB. At the end of the 2 month period in which the coupons are valid the index will receive a grocery voucher for the total incentive earned (e.g., total amount for contact(s) who presented for screening + total amount for contact(s) diagnosed with active TB and starting treatment).

This includes both arms of contact investigation (household-based and incentive-based) combined together into one group from which to calculate the incremental cost-effectiveness ratio