Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03667079 |
| Other study ID # |
14674-001 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
February 1, 2016 |
| Est. completion date |
December 31, 2016 |
Study information
| Verified date |
April 2023 |
| Source |
Washington State University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The overarching goal of this project is the elimination of two neglected tropical diseases
(NTD):
soil-transmitted helminthiasis and rabies. The specific objective of this pilot study was:
To determine whether the integrated delivery platform improved the cost-effectiveness and
coverage of MDA targeting STH and rabies;
The investigators integrated two public health initiatives: 1) a mass drug administration
(MDA) effort to eliminate neglected tropical diseases (NTD) caused by soil-transmitted
helminths (STH), with 2) a community-valued mass dog rabies vaccination (MDRV) intervention
to eliminate human and animal rabies, also a priority NTD of the World Health Organisation.
The goal of MDA efforts targeting STH is to reduce worm burdens to very low levels below
which self-sustaining transmission, and the public health consequences of STH, cease.
Existing school-based delivery programs fail to reach all affected age groups, however, which
results in ineffective coverage levels and persistence of STH. The goal of MDRV is to
immunize 70% of dog populations, after which canine-mediated rabies is eliminated. MDRV
programs are typically very popular, with all human age groups participating. The objectives
of this project were to determine whether supplementing a strictly school-based MDA NTD
control program with a community-wide strategy that is coupled to an MDRV program will result
in a synergism that (a) improves coverage, reach and cost-effective delivery of MDA targeting
STH and (b) improves coverage and cost-effective delivery of dog vaccination. To achieve
this, research activities, comprised of post-intervention household questionnaire surveys,
were carried out. In addition detailed cost data was collected.
Description:
The study was carried out in the Ngorongoro District, Tanzania inhabited by semi-nomadic
Maasai people. The remote area was chosen because MDRV and MDA are carried out annually in
the region as separate programs. The MDA program delivers twice yearly deworming treatment to
every primary school and is coordinated by the District Medical Office (DMO). The MDRV
program vaccinates dogs annually and is coordinated by the District Veterinary Office. The
MDA and MDRV carried out in this study constituted one cycle of the established MDA and MDRV
in the target villages. The study took place between February and October 2016, however
activities were suspended during the rainy season to avoid inclement weather from affecting
participation.
The study focused on 24 villages. The target villages were located within the eight wards
immediately surrounding the district's administrative centre and were selected through
convenience. Each of the 24 villages were randomly assigned to one of three arms: i) Arm A (n
= 8) received both MDA and MDRV; ii) Arm B (n = 8) received MDA only; iii) Arm C (n = 8)
received MDRV only. All villages were equally likely to be assigned to each arm. As per the
established MDA and MDRV programs, a nurse from the DMO and two village-based community
health workers carried out the MDA whilst a rabies field team (a veterinarian, two field
staff and a ward-based person) delivered the MRDV. STH and / or rabies awareness information
was provided to respondents in the form of verbal disease avoidance advice.
Villages in this region cover a large area, and all are divided into sub-village units. Each
intervention ('event') was delivered at the level of the sub-village using a 'central-point'
strategy, which required villagers to travel from their homes to the central-point event to
receive treatment. Village leaders estimated that hosting each sub-village event for one day
would provide sufficient time for villagers to attend. Consequently each event was scheduled
to last for one day, and the number of days the team(s) spent in each village equalled the
number of sub-villages.
Arm A events comprised an MDA and a MDRV clinic hosted concurrently, while Arm B and Arm C
events comprised only one clinic (MDA or MDRV, respectively). For Arm A villages, the MDA and
MDRV delivery teams travelled together in one vehicle and set up the clinics close to each
other. For Arm B and C villages, the MDA and MDRV teams travelled separately.
In order to allow comparison of the MDA with school-based delivery (second objective) the
events were all hosted during the school term. In sub-villages with a primary school, the
clinics were positioned outside the school grounds, whilst in sub-villages that did not have
a primary school the clinics were located in a central location.
To inform each community of the event, a village-wide meeting was convened one week before.
Key information provided at the meeting included STH and / or rabies awareness information
and the importance of controlling these conditions through MDA and MDRV, the date of each
clinic, that treatment would be given free of charge, and that people and dogs of all ages
were invited to attend. On the Sunday prior to a village event, a motorbike rider with a
loudspeaker drove around each village announcing the event details. Additionally the DMO
informed the head teacher of each primary school of the date that the event would be convened
outside of the school grounds. At 0830 hours the clinic(s) would be set up in the
predetermined location and the treatment teams would wait for villagers to arrive. People
coming to the MDA clinic were registered and research data collected. Following this,
children between 12 and 59 months were given an oral dose of mebendazole (500mg) and vitamin
A (100,000 IU), whilst people over 59 months were given an oral dose of albendazole (400mg).
Following arrival and registration at the MDRV clinics, dogs were vaccinated (Nobivac
Rabies®, MSD Animal Health, Boxmeer, Netherlands), a collar placed around the neck and
water-soluble purple coloured paint was applied to both flanks. People attending the combined
clinic (Arm A) who had also brought dogs were instructed to visit the MDRV clinic after
receiving deworming treatment. The events ended at 1630 hours.
Household participation and coverage - community perceptions and knowledge:
A post-intervention household questionnaire survey (HQS) targeting 30 randomly selected
households per village (stratified across sub-villages) was carried out within one week of
each intervention to determine the proportion of households, people and dogs that attended
the clinics. No households declined to participate, however if the family were not at home
the team moved onto the next household.
Coverage of school-aged children and others:
To calculate the percentage of treated primary school age children (7 - 13 years) that were
enrolled or not in school, or were attending or not attending school on the day of the
clinic, every person treated was asked whether they were enrolled and attending primary
school that day and, if they attended primary school, which primary school they attended.
Every participant was also asked their age, which allowed analysis of other age groups
treated.
Chi squared tests were used to determine whether household participation and coverage were
impacted by delivery strategy. A logistic regression model (logit family) was used to
determine whether the proportion of children enrolled in primary school in each village was
dependent on the presence of a school.
Comparison with the national school-based deworming program:
To determine whether delivery strategy and clinic location (outside of school grounds with
the whole community invited (this study) or within the schools with treatment given only to
enrolled school children (NSDP)) impacted the number of school children that received
deworming treatment, a paired comparison at ten village primary schools was made. To allow
comparison, the number of primary school children treated in the previous NSDP round of
deworming treatment was obtained for each of the ten schools from the Ngorongoro District NTD
Coordinator and compared with the number of registered children treated in this study in the
same schools.
A generalized linear mixed model, with 'school name' as a random effect, was used to compare
the proportion of primary school children treated by the NSDP and this study in each
comparison school.
Administration and delivery costs:
Clinic administration and delivery (A&D) costs were collected for all 24 villages, including
variable costs (per dose delivered, by dose type) and fixed costs (per clinic, by clinic
type). Expense categories included: Advertising, Equipment, Incentive payments to village
leaders, Labour Costs (team salaries and wage labour for local help), Living (lodging)
Allowance, Per Diem for the team, Meeting Costs, Vehicle Fuel, Repairs and Service,
Communication (telephone credits), and Other. Other included a variety of miscellaneous costs
that do not fit under any other category, such as incidental taxi and transportation costs
and team health treatment. Costs attributable to research-related activities were not
included in A&D costs. Indirect costs (time, foregone opportunities) borne by households to
attend the event (described above) were not included in A&D costs. For accounting purposes,
fixed costs not attributable to a specific clinic type were allocated equally across all
events. Fixed costs attributable to either MDRV or MDA were attributed equally across all
rabies or deworming events, respectively. Because there were two clinics for each Arm A
event, the unattributable fixed cost per clinic was half that of Arm B and C. Variable costs
per clinic were calculated as per-dose purchase costs multiplied by the number of doses
delivered. Per-dose purchase costs were $0.021 (44 Tanzanian Shillings [Tsh]) per deworming
dose and $0.26 (520 Tsh) per rabies vaccination. The exchange rate for cost calculations was
2,100 Tsh per U.S. Dollar, approximately the exchange rate that prevailed from mid-2015
through 2016.
The average cost per dose (A&D) was calculated in two ways. Method 1 calculates the total
cost over all clinics (by clinic type and Arm) divided by the total number of doses delivered
(by clinic type and Arm), and represents the aggregate cost per dose for a given clinic
category. Method 2 calculates cost per dose on a per clinic basis, and then averages over all
clinics. Both methods provide valid measures of cost per dose (A&D), but provide different
estimates, because the average of a ratio (Method 2) is not equivalent to the ratio of
averages or totals (Method 1). Method 1 is useful as an aggregate measure over all clinics,
but cannot be used to test for statistical differences across clinic categories because it is
not calculated on a per clinic basis. Method 2 allows testing for statistical differences
across clinic types, but represents a summary statistic for clinic-level cost per dose
measure rather than an aggregate measure.
Two-sample parametric and non-parametric tests were used to test for differences in cost per
dose between Arms A and B, and Arms A and C.
Travel time to attend clinics:
To understand which mode of transport was most commonly used, respondents were asked how they
travelled to the clinic (foot, carried (e.g. infants), bike, car, etc.). To estimate the mean
time (t ̅_1) a respondent took attending a combined or single event, respondents were asked
how long it took in minutes to reach the events. In addition, the mean amount of time a
respondent spent at a clinic (t ̅_2) and, for the integrated delivery (Arm A) the mean time
spent travelling between the two clinics (t ̅_3), was measured. These estimates were then
used to compare the overall time spent attending single and integrated events. To estimate
the overall time a respondent spent attending a single clinic (Arm B or C, or Arm A if no dog
was brought for vaccination) (T_s) we multiplied the mean travel time by two (for the out and
return journey) and added the mean time spent at a clinic:
T_s=(t ̅_1 × 2)+ t ̅_2.
To estimate the mean time a respondent spent attending a combined clinic (Arm A) (T_c ) we
multiplied the mean travel time by two and added the mean time spent at a clinic (multiplied
by two for deworming and dog vaccination) and the time spent travelling between the two
clinics:
T_c=(t ̅_1× 2)+(t ̅_2× 2)+ t ̅_3.
