Care Rapid Influenza Test on Antibiotic Prescribing Patterns in So

85 Pages·2014·3.5 MB·English

by  Gayani Tillekeratne

Impact  of  a  Point-­‐‑of-­‐‑Care  Rapid  Influenza  Test  on  Antibiotic  Prescribing  Patterns  in  
Southern  Sri  Lanka  
by  
L.  Gayani  Tillekeratne  
Duke  Global  Health  Institute  

Date:_______________________  
Approved:  

___________________________  
Christopher  W.  Woods,  Supervisor  

___________________________  
Nathan  M.  Thielman  

___________________________  
Truls  Ostbye  

___________________________  
Champica  K.  Bodinayake  

___________________________  
Megan  E.  Reller  

Thesis  submitted  in  partial  fulfillment  of  
the  requirements  for  the  degree  of  
Master  of  Science  in  the  Duke  Global  Health  Institute  in  the  Graduate  School  of  Duke  
University  

2014
ABSTRACT  
Impact  of  a  Point-­‐‑of-­‐‑Care  Rapid  Influenza  Test  on  Antibiotic  Prescribing  Patterns  in  
Southern  Sri  Lanka  
by  
L.  Gayani  Tillekeratne  
Department  of  Global  Health  
Duke  University  

Date:_______________________  
Approved:  

___________________________  
Christopher  W.  Woods,  Supervisor  

___________________________  
Nathan  M.  Thielman  

___________________________  
Truls  Ostbye  

___________________________  
Champica  K.  Bodinayake  

___________________________  
Megan  E.  Reller  

An  abstract  of  a  thesis  submitted  in  partial  
fulfillment  of  the  requirements  for  the  degree  
of  Master  of  Science  in  the  Duke  Global  Health  Institute  in  the  Graduate  School  of  Duke  
University  

2014
Copyright  by  
L.  Gayani  Tillekeratne  
2014
Abstract  
Background:  Acute  febrile  respiratory  illnesses,  including  influenza,  account  for  
a  large  proportion  of  ambulatory  care  visits  worldwide.  In  the  developed  world,  these  
encounters  commonly  result  in  unwarranted  antibiotic  prescriptions;  data  from  more  
resource-­‐‑limited  settings  are  lacking.    The  purpose  of  this  study  was  to  describe  the  
epidemiology  of  influenza  among  outpatients  in  southern  Sri  Lanka  and  to  determine  if  
access  to  rapid  influenza  test  results  was  associated  with  decreased  antibiotic  
prescriptions.  
Methods:    In  this  pretest-­‐‑  posttest  study,  consecutive  patients  presenting  from  
March  2013-­‐‑  April  2014  to  the  Outpatient  Department  of  the  largest  tertiary  care  hospital  
in  southern  Sri  Lanka  were  surveyed  for  influenza-­‐‑like  illness  (ILI).  Patients  meeting  
World  Health  Organization  criteria  for  ILI-­‐‑-­‐‑  acute  onset  of  fever  ≥38.0°C  and  cough  in  
the  prior  7  days—were  enrolled.  Consenting  patients  were  administered  a  structured  
questionnaire,  physical  examination,  and  nasal/nasopharyngeal  sampling.  Rapid  
influenza  A/B  testing  (Veritor  System,  Becton  Dickinson)  was  performed  on  all  patients,  
but  test  results  were  only  released  to  patients  and  clinicians  during  the  second  phase  of  
the  study  (December  2013-­‐‑  April  2014).    
Results:    We  enrolled  397  patients  with  ILI,  with  217  (54.7%)  adults  ≥12  years  and  
188  (47.4%)  females.  A  total  of  179  (45.8%)  tested  positive  for  influenza  by  rapid  testing,  

iv
with  April-­‐‑  July  2013  and  September-­‐‑  November  2013  being  the  periods  with  the  highest  
proportion  of  ILI  due  to  influenza.  A  total  of  310  (78.1%)  patients  with  ILI  received  a  
prescription  for  an  antibiotic  from  their  outpatient  provider.  The  proportion  of  patients  
prescribed  antibiotics  decreased  from  81.4%  in  the  first  phase  to  66.3%  in  the  second  
phase  (p=.005);  among  rapid  influenza-­‐‑positive  patients,  antibiotic  prescriptions  
decreased  from  83.7%  in  the  first  phase  to  56.3%  in  the  second  phase  (p=.001).  On  
multivariable  analysis,  having  a  positive  rapid  influenza  test  available  to  clinicians  was  
associated  with  decreased  antibiotic  use  (OR  0.20,  95%  CI  0.05-­‐‑  0.82).  
Conclusions:  Influenza  virus  accounted  for  almost  50%  of  acute  febrile  
respiratory  illness  in  this  study,  but  most  patients  were  prescribed  antibiotics.  Providing  
rapid  influenza  test  results  to  clinicians  was  associated  with  fewer  antibiotic  
prescriptions,  but  overall  prescription  of  antibiotics  remained  high.  In  this  developing  
country  setting,  a  multi-­‐‑faceted  approach  that  includes  improved  access  to  rapid  
diagnostic  tests  may  help  decrease  antibiotic  use  and  combat  antimicrobial  resistance.  

v
Contents  
Abstract  ..........................................................................................................................................  iv

List  of  Tables  .................................................................................................................................  ix

List  of  Figures  ...............................................................................................................................  xi

Acknowledgements  ....................................................................................................................  xii

1. Background  ................................................................................................................................  1

1.1  Global  burden  and  seasonality  of  influenza  .................................................................  1

1.2  Epidemiology  of  influenza  in  Sri  Lanka  ........................................................................  3

1.3  Influenza,  antibiotic  use,  and  the  impact  of  rapid  diagnostic  testing  .......................  5

2. Objectives  ..................................................................................................................................  8

3. Setting  .........................................................................................................................................  9

3.1  Background  on  Sri  Lanka  and  its  healthcare  infrastructure  ......................................  9

3.2  Duke-­‐‑Ruhuna  Collaboration  .........................................................................................  10

4. Methods  ....................................................................................................................................  12

4.1  Study  setting  ....................................................................................................................  12

4.2  Study  procedures  ............................................................................................................  12

4.3  Sample  processing  ..........................................................................................................  13

4.4  Study  design  ....................................................................................................................  15

4.5  Analysis  plan  ...................................................................................................................  16

4.6  Ethical  considerations  ....................................................................................................  17

5. Results  ......................................................................................................................................  18

5.1.  Description  of  study  population  .................................................................................  22

vi
5.1.1  Sociodemographic  characteristics  ...........................................................................  22

5.1.2  Exposures  and  risk  factors  .......................................................................................  26

5.1.3  Prior  care  .....................................................................................................................  27

5.1.4  Clinical  presentation  .................................................................................................  28

5.1.5  Rapid  influenza  test  results  ......................................................................................  30

5.1.6  Clinical  management  ................................................................................................  34

5.1.7  Impact  on  finances  and  productivity  ......................................................................  34

5.2  Comparison  of  first  and  second  phases  ......................................................................  35

5.2.1  Sociodemographic  characteristics,  exposures,  and  impact  on  finances  and  
productivity  .........................................................................................................................  35

5.2.2  Clinical  characteristics  and  physical  exam  findings  .............................................  36

5.2.3  Rapid  influenza  test  results  and  clinical  management  ........................................  37

5.3  Bivariable  analysis  of  features  associated  with  influenza  ........................................  38

5.3.1  Sociodemographic  characteristics,  exposures,  and  clinical  symptoms  .............  38

5.3.2  Clinical  management  ................................................................................................  39

5.4  Bivariable  analysis  of  features  associated  with  antibiotic  prescriptions  ................  43

5.4.1  Sociodemographic  characteristics,  exposures,  and  clinical  symptoms  .............  43

5.4.2  Clinical  management  ................................................................................................  43

5.5  Multivariable  analysis  of  features  associated  with  influenza  ..................................  48

5.6  Multivariable  analysis  of  features  associated  with  receipt  of  an  antibiotic  
prescription  ............................................................................................................................  49

6. Discussion  ................................................................................................................................  51

6.1  ILI  and  influenza  patterns  in  southern  Sri  Lanka  ......................................................  51

vii
6.2  Clinical  presentation  of  influenza  ................................................................................  55

6.3  ILI  and  antibiotic  use  ......................................................................................................  56

7. Ongoing work  ..........................................................................................................................  66

8. Conclusions  .............................................................................................................................  67

Appendix A  ...................................................................................................................................  68

References  ...................................................................................................................................  70

viii
List  of  Tables  
Table  1:  Sociodemographic  characteristics  of  outpatients  enrolled  with  ILI  in  southern  
Sri  Lanka  from  March  2013-­‐‑  April  2014,  listed  for  the  entire  study  population  as  well  as  
for  each  phase  of  the  study.  .......................................................................................................  25

Table  2:  Exposures  and  risk  factors  for  outpatients  with  ILI  in  southern  Sri  Lanka,  March  
2013-­‐‑  April  2014,  listed  for  the  entire  study  population  as  well  as  for  each  phase  of  the  
study.  .............................................................................................................................................  27

Table  3:  Clinical  symptoms,  exam  findings,  and  clinical  diagnoses  and  treatment  
received  among  outpatients  with  ILI  in  southern  Sri  Lanka,  March  2013  to  April  2014  ..  29

Table  4:  Impact  of  illness  on  finances  and  productivity  among  outpatients  with  ILI  in  
southern  Sri  Lanka  from  March  2013-­‐‑  April  2014,  listed  for  the  total  study  population  as  
well  as  for  each  phase  of  the  study.  ..........................................................................................  35

Table  5:  Bivariable  analysis  of  sociodemographic  characteristics,  exposures,  and  clinical  
characteristics  associated  with  rapid  influenza  positivity  among  outpatients  with  ILI  in  
southern  Sri  Lanka,  March  2013-­‐‑  April  2014.  ..........................................................................  40

Table  6:  Bivariable  analysis  of  cost  and  productivity  variables  associated  with  rapid  
influenza  positivity  among  outpatients  with  ILI  in  southern  Sri  Lanka,  March  2013-­‐‑  
April  2014.  ....................................................................................................................................  42

Table  7:  Bivariable  analysis  of  clinical  diagnoses  and  treatments  associated  with  rapid  
influenza  positivity  in  outpatients  with  ILI  in  southern  Sri  Lanka,  March  2013-­‐‑  April  
2014  ................................................................................................................................................  42

Table  8:  Bivariable  analysis  of  sociodemographic  characteristics  and  clinical  features  
associated  with  antibiotic  prescriptions  for  outpatients  with  ILI  in  southern  Sri  Lanka,  
March  2013-­‐‑  April  2014.  .............................................................................................................  45

Table  9:  Bivariable  analysis  of  cost  and  productivity  variables  associated  with  antibiotic  
prescriptions  for  outpatients  with  ILI  in  southern  Sri  Lanka,  March  2013-­‐‑  April  2014.  ...  47

Table  10:  Bivariable  analysis  of  clinical  diagnoses  and  treatments  associated  with  
antibiotic  prescriptions  for  outpatients  with  ILI  in  southern  Sri  Lanka,  March  2013-­‐‑  April  
2014.  ...............................................................................................................................................  47

ix
Table  11:  Multivariable  analysis  of  sociodemographic  characteristics,  exposures,  clinical  
symptoms,  and  exam  findings  associated  with  rapid  influenza  positivity  among  
outpatients  with  ILI  in  southern  Sri  Lanka,  March  2013-­‐‑  April  2014.  .................................  49

Table  12:  Multivariable  analysis  of  sociodemographic  characteristics,  exposures,  clinical  
symptoms,  and  exam  findings  associated  with  antibiotic  prescriptions  among  
outpatients  with  ILI  in  southern  Sri  Lanka,  March  2013-­‐‑  April  2014.  .................................  50

x