-
Notifications
You must be signed in to change notification settings - Fork 0
/
Breastfeeding withheld.Rmd
682 lines (558 loc) · 35.2 KB
/
Breastfeeding withheld.Rmd
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
---
output:
html_document:
theme: yeti
toc: true
toc_depth: 3
toc_float:
collapsed: false
title: "Breastfeeding withheld"
### Written by Edward Parker ([email protected]), 29 May 2018
---
## Full analysis
```{r, echo=FALSE, message=FALSE, warning=FALSE}
# Load packages required for meta-analysis
library(metafor)
library(forestplot)
library(ggplot2)
# Import data and plot settings
data = read.csv("Church_et_al_2018_metaregression_input.csv",header=TRUE, stringsAsFactors=FALSE)
settings = read.csv("Church_et_al_2018_plot_settings.csv",header=TRUE, stringsAsFactors=FALSE)
# Select intervention, then subset data
intervention = "Breastfeeding withheld"
data1 = subset(data, Intervention_category==intervention)
# Replace '--' with '-' characters in age column
data1$Age_formatted = gsub("--", "-", data1$Age_formatted)
# Set plotting parameters for selected intervention (axis limits, plot height, plot width, and footnote coordinates)
forest_x_min_main = settings[which(settings$intervention==intervention),"forest_x_min_main"]
forest_x_max_main = settings[which(settings$intervention==intervention),"forest_x_max_main"]
forest_x_min_polio = settings[which(settings$intervention==intervention),"forest_x_min_polio"]
forest_x_max_polio = settings[which(settings$intervention==intervention),"forest_x_max_polio"]
plot_width_main = settings[which(settings$intervention==intervention),"plot_width_main"]
plot_width_polio = settings[which(settings$intervention==intervention),"plot_width_polio"]
plot_height_main = settings[which(settings$intervention==intervention),"plot_height_main"]
plot_height_polio = settings[which(settings$intervention==intervention),"plot_height_polio"]
footnote_x_main = settings[which(settings$intervention==intervention),"footnote_x_main"]
footnote_y_main = settings[which(settings$intervention==intervention),"footnote_y_main"]
footnote_x_polio = settings[which(settings$intervention==intervention),"footnote_x_polio"]
footnote_y_polio = settings[which(settings$intervention==intervention),"footnote_y_polio"]
column_gap_main = settings[which(settings$intervention==intervention),"column_gap_main"]
# Create subsets of data for each vaccine target
input_cholera = subset(data1,Vaccine=="Cholera")
input_rota = subset(data1,Vaccine=="Rotavirus")
input_PV1 = subset(data1,Measure_of_SC=="OPV1 N-AB")
input_PV2 = subset(data1,Measure_of_SC=="OPV2 N-AB")
input_PV3 = subset(data1,Measure_of_SC=="OPV3 N-AB")
# Create two collated versions of dataset - one for CV, RV and PV3; one for all types of polio
input_all = rbind(input_cholera, input_rota, input_PV3)
input_PV_all = rbind(input_PV1, input_PV2, input_PV3)
# Set minimum study count for inclusion in meta-analysis
min = 2
```
```{r, echo=FALSE, message=FALSE, warning=FALSE}
# Calculate sums of N by vaccine
cholera_sum = sum(input_all$Total[input_all$Vaccine=="Cholera"])
rota_sum = sum(input_all$Total[input_all$Vaccine=="Rotavirus"])
polio_sum = sum(input_all$Total[input_all$Vaccine=="Polio"])
overall_sum = sum(input_all$Total)
# Calculate number of vaccines included in analysis
n_vaccines = as.numeric(cholera_sum>0) + as.numeric(rota_sum>0) + as.numeric(polio_sum>0)
# Calculate summary statistics for each subset
if (cholera_sum>0) { data_cholera = escalc(measure = "RR", ai = Int_SC_n, bi = Int_N-Int_SC_n, ci = Ctrl_SC_n, di = Ctrl_N-Ctrl_SC_n, data = input_cholera, append = TRUE) }
if (rota_sum>0) { data_rota = escalc(measure = "RR", ai = Int_SC_n, bi = Int_N-Int_SC_n, ci = Ctrl_SC_n, di = Ctrl_N-Ctrl_SC_n, data = input_rota, append = TRUE) }
if (polio_sum>0) { data_PV3 = escalc(measure = "RR", ai = Int_SC_n, bi = Int_N-Int_SC_n, ci = Ctrl_SC_n, di = Ctrl_N-Ctrl_SC_n, data = input_PV3, append = TRUE) }
data_all = escalc(measure = "RR", ai = Int_SC_n, bi = Int_N-Int_SC_n, ci = Ctrl_SC_n, di = Ctrl_N-Ctrl_SC_n, data = input_all, append = TRUE)
# Perform REML meta-analyses
if (cholera_sum>0) { meta_cholera = rma(yi, vi, data = data_cholera, method = "REML") }
if (rota_sum>0) { meta_rota = rma(yi, vi, data = data_rota, method = "REML") }
if (polio_sum>0) { meta_PV3 = rma(yi, vi, data = data_PV3, method = "REML") }
# Perform combined meta-analysis, including random effect on study ID if intervention is 'RVV separated from OPV' (to account for replication of infants for RVV and OPV outcomes)
if (intervention=="RVV separated from OPV") { meta_all = rma.mv(yi, vi, data = data_all, method = "REML", random = ~ 1 | Reference) }
if (intervention!="RVV separated from OPV") { meta_all = rma(yi, vi, data = data_all, method = "REML") }
# Perform mixed-effects meta-regression, including random effect on study ID for 'RVV separated from OPV'
if (nrow(data_all)>=min & n_vaccines>1 & intervention=="RVV separated from OPV") { mixed_all = rma.mv(yi, vi, mods = ~ Vaccine, data = data_all, method = "REML", random = ~ 1 | Reference) }
if (nrow(data_all)>=min & n_vaccines>1 & intervention!="RVV separated from OPV") { mixed_all = rma(yi, vi, mods = ~ Vaccine, data = data_all, method = "REML") }
if (n_vaccines==1) {
mixed_all = NA
mixed_all$QEp = mixed_all$QMp = 1 } # if there is only 1 vaccine type, assign arbitrary value of 1 to mixed_all p values so as to avoid errors in later logical operators
# Create function to extract RRs and CIs from individual studies in rma meta-analysis output
RR_CIs = function(x) {
paste0(formatC(round(exp(x$yi),2),format='f',digits=2)," (",formatC(round(exp(x$yi-1.96*sqrt(x$vi)),2),format='f',digits=2),"-",formatC(round(exp(x$yi+1.96*sqrt(x$vi)),2),format='f',digits=2),")")
}
# Create function to extract overall RRs and CIs from rma meta-analysis output
RR_summary = function(x) {
paste0(formatC(round(exp(x$b),2),format='f',digits=2)," (", formatC(round(exp(x$b-1.96*x$se),2),format='f',digits=2), "-", formatC(round(exp(x$b+1.96*x$se),2),format='f',digits=2),")")
}
# Create function to collate relevant data for each column of forest plot
table_column = function(column_title, ref) {
column = column_title # specify column title
if (nrow(input_cholera)>0) { column = c(column,NA,input_cholera[,ref]) } # add study-specific rows if there is at least one study
if (nrow(input_cholera)<min & nrow(input_cholera)>0) { column = c(column,NA) } # add gap if number of studies is <min
if (nrow(input_cholera)>=min) { column = c(column,NA,NA) } # add summary row if number of studies is >=min
if (nrow(input_rota)>0) { column = c(column,NA,input_rota[,ref]) }
if (nrow(input_rota)<min & nrow(input_rota)>0) { column = c(column,NA) }
if (nrow(input_rota)>=min) { column = c(column,NA,NA) }
if (nrow(input_PV3)>0) { column = c(column,NA,input_PV3[,ref]) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { column = c(column,NA) }
if (nrow(input_PV3)>=min) { column = c(column,NA,NA) }
if (nrow(input_all)>=min & n_vaccines>1) { column = c(column,NA) }
if (nrow(input_all)>=min & n_vaccines==1) { column = column[-length(column)] }
return(column)
}
# Use function to create meta-data columns for forest plot
country = table_column(column_title="Country", ref="Country")
age = table_column(column_title="Age (m)", ref="Age_formatted")
vaccine = table_column(column_title="Vaccine", ref="Vaccine_formatted")
intervention_col = table_column(column_title="Intervention", ref="Intervention_formatted")
N_int = table_column(column_title="n/N (%)", ref="Int_SC_full")
control = table_column(column_title="Control", ref="Control_formatted")
N_ctrl = table_column(column_title="n/N (%)", ref="Ctrl_SC_full")
# Create first column composed of Study IDs and vaccine names
titles = "Study"
if (nrow(input_cholera)>0) { titles = c(titles,"Cholera",input_cholera$Reference) }
if (nrow(input_cholera)<min & nrow(input_cholera)>0) { titles = c(titles,NA) }
if (nrow(input_cholera)>=min) { titles = c(titles,"Summary",NA) }
if (nrow(input_rota)>0) { titles = c(titles,"Rotavirus",input_rota$Reference) }
if (nrow(input_rota)<min & nrow(input_rota)>0) { titles = c(titles,NA) }
if (nrow(input_rota)>=min) { titles = c(titles,"Summary",NA) }
if (nrow(input_PV3)>0) { titles = c(titles,"OPV3",input_PV3$Reference) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { titles = c(titles,NA) }
if (nrow(input_PV3)>=min) { titles = c(titles,"Summary",NA) }
if (nrow(input_all)>=min & n_vaccines>1) { titles = c(titles, "Overall") }
if (nrow(input_all)>=min & n_vaccines==1) { titles = titles[-length(titles)] }
# Create final column composed of RRs and 95% CIs
RRs = "RR (95% CI)"
if (nrow(input_cholera)>0) { RRs = c(RRs,NA,RR_CIs(meta_cholera)) }
if (nrow(input_cholera)<min & nrow(input_cholera)>0) { RRs = c(RRs,NA) }
if (nrow(input_cholera)>=min) { RRs = c(RRs,RR_summary(meta_cholera),NA) }
if (nrow(input_rota)>0) { RRs = c(RRs,NA,RR_CIs(meta_rota)) }
if (nrow(input_rota)<min & nrow(input_rota)>0) { RRs = c(RRs,NA) }
if (nrow(input_rota)>=min) { RRs = c(RRs,RR_summary(meta_rota),NA) }
if (nrow(input_PV3)>0) { RRs = c(RRs,NA,RR_CIs(meta_PV3)) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { RRs = c(RRs,NA) }
if (nrow(input_PV3)>=min) { RRs = c(RRs,RR_summary(meta_PV3),NA) }
if (nrow(input_all)>=min & n_vaccines>1) { RRs = c(RRs,RR_summary(meta_all)) }
if (nrow(input_all)>=min & n_vaccines==1) { RRs = RRs[-length(RRs)] }
# Collate forest plot text
tabletext = cbind(titles, country, age, vaccine, intervention_col, N_int, control, N_ctrl, RRs)
# Create variable composed of RRs
m = NA
if (nrow(input_cholera)>0) { m = c(m,NA,meta_cholera$yi) }
if (nrow(input_cholera)<min & nrow(input_cholera)>0) { m = c(m,NA) }
if (nrow(input_cholera)>=min) { m = c(m,meta_cholera$b,NA) }
if (nrow(input_rota)>0) { m = c(m,NA,meta_rota$yi) }
if (nrow(input_rota)<min & nrow(input_rota)>0) { m = c(m,NA) }
if (nrow(input_rota)>=min) { m = c(m,meta_rota$b,NA) }
if (nrow(input_PV3)>0) { m = c(m,NA,meta_PV3$yi) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { m = c(m,NA) }
if (nrow(input_PV3)>=min) { m = c(m,meta_PV3$b,NA) }
if (nrow(input_all)>=min & n_vaccines>1) { m = c(m,meta_all$b) }
if (nrow(input_all)>=min & n_vaccines==1) { m = m[-length(m)] }
# Create variables for lower CI limits of RR estimates
l = NA
if (nrow(input_cholera)>0) { l = c(l,NA,meta_cholera$yi-sqrt(meta_cholera$vi)*1.96) }
if (nrow(input_cholera)<min & nrow(input_cholera)>0) { l = c(l,NA) }
if (nrow(input_cholera)>=min) { l = c(l,meta_cholera$b-meta_cholera$se*1.96,NA) }
if (nrow(input_rota)>0) { l = c(l,NA,meta_rota$yi-sqrt(meta_rota$vi)*1.96) }
if (nrow(input_rota)<min & nrow(input_rota)>0) { l = c(l,NA) }
if (nrow(input_rota)>=min) { l = c(l,meta_rota$b-meta_rota$se*1.96,NA) }
if (nrow(input_PV3)>0) { l = c(l,NA,meta_PV3$yi-sqrt(meta_PV3$vi)*1.96) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { l = c(l,NA) }
if (nrow(input_PV3)>=min) { l = c(l,meta_PV3$b-meta_PV3$se*1.96,NA) }
if (nrow(input_all)>=min & n_vaccines>1) { l = c(l,meta_all$b-meta_all$se*1.96) }
if (nrow(input_all)>=min & n_vaccines==1) { l = l[-length(l)] }
# Create variables for upper CI limits of RR estimates
u = NA
if (nrow(input_cholera)>0) { u = c(u,NA,meta_cholera$yi+sqrt(meta_cholera$vi)*1.96) }
if (nrow(input_cholera)<min & nrow(input_cholera)>0) { u = c(u,NA) }
if (nrow(input_cholera)>=min) { u = c(u,meta_cholera$b+meta_cholera$se*1.96,NA) }
if (nrow(input_rota)>0) { u = c(u,NA,meta_rota$yi+sqrt(meta_rota$vi)*1.96) }
if (nrow(input_rota)<min & nrow(input_rota)>0) { u = c(u,NA) }
if (nrow(input_rota)>=min) { u = c(u,meta_rota$b+meta_rota$se*1.96,NA) }
if (nrow(input_PV3)>0) { u = c(u,NA,meta_PV3$yi+sqrt(meta_PV3$vi)*1.96) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { u = c(u,NA) }
if (nrow(input_PV3)>=min) { u = c(u,meta_PV3$b+meta_PV3$se*1.96,NA) }
if (nrow(input_all)>=min & n_vaccines>1) { u = c(u,meta_all$b+meta_all$se*1.96) }
if (nrow(input_all)>=min & n_vaccines==1) { u = u[-length(u)] }
```
### Forest plot
```{r, echo=FALSE, message=FALSE, warning=FALSE, fig.width=plot_width_main, fig.height=plot_height_main}
# Create function to assign colours to meta-analysis boxes and lines
# Adapted from: https://stackoverflow.com/questions/46938910
fn <- local({
i = 0
b_clrs = vector()
if (nrow(input_cholera)>0) { b_clrs = rep("#90B11F", nrow(input_cholera)) }
if (nrow(input_rota)>0) { b_clrs = c(b_clrs, rep("#D43E55", nrow(input_rota))) }
if (nrow(input_PV3)>0) { b_clrs = c(b_clrs, rep("#F1A44F", nrow(input_PV3))) }
b_clrs = c(b_clrs, "black")
l_clrs = rep("grey", length(b_clrs))
# l_clrs = b_clrs # use this line instead of the line above to make lines the same colour as the boxes
function(..., clr.line, clr.marker){
i <<- i + 1
fpDrawNormalCI(..., clr.line = l_clrs[i], clr.marker = b_clrs[i])
}
})
# Create function to assign colours to meta-analysis summary diamonds
# Adapted from: https://stackoverflow.com/questions/46938910
fn_sum <- local({
i = 0
b_clrs_sum = vector()
if (nrow(input_cholera)>=min) { b_clrs_sum = "#90B11F" }
if (nrow(input_rota)>=min) { b_clrs_sum = c(b_clrs_sum, "#D43E55") }
if (nrow(input_PV3)>=min) { b_clrs_sum = c(b_clrs_sum, "#F1A44F") }
b_clrs_sum = c(b_clrs_sum, "black")
function(..., col){
i <<- i + 1
fpDrawSummaryCI(..., col = b_clrs_sum[i])
}
})
# Create forest plot
if (nrow(input_all)>=min) {
forestplot(tabletext,exp(m),exp(l),exp(u),zero=1,
is.summary=c(TRUE,TRUE,!is.na(tabletext[3:nrow(tabletext),1]) & (tabletext[3:nrow(tabletext),1]=="Summary" | tabletext[3:nrow(tabletext),1]=="Overall"| tabletext[3:nrow(tabletext),1]=="Cholera"| tabletext[3:nrow(tabletext),1]=="Rotavirus"| tabletext[3:nrow(tabletext),1]=="OPV3")),
clip=c(forest_x_min_main,forest_x_max_main), xlog=TRUE,
xticks=c(forest_x_min_main,1,forest_x_max_main),
fn.ci_norm=fn,
fn.ci_sum=fn_sum,
colgap=unit(column_gap_main,"mm"),
txt_gp = fpTxtGp(ticks = gpar(cex=0.8))
)
# Add footnote containing heterogeneity results
if (nrow(data_all)>=min & n_vaccines>1 & mixed_all$QEp>=0.0001) {
grid.text(paste0("Heterogeneity among vaccines (Qm ", formatC(round(mixed_all$QM,2),format='f',digits=2), ", df ", mixed_all$m, "), p = ", formatC(round(mixed_all$QMp,3),format='f',digits=3),
"; Residual heterogeneity (Qe ", formatC(round(mixed_all$QE,2),format='f',digits=2), ", df ", mixed_all$k-mixed_all$p, "), p = ", formatC(round(mixed_all$QEp,3),format='f',digits=3)),
footnote_x_main, footnote_y_main, gp = gpar(fontsize=12, font = "sans")) }
if (nrow(data_all)>=min & n_vaccines>1 & mixed_all$QEp<0.0001) {
grid.text(paste0("Heterogeneity among vaccines (Qm ", formatC(round(mixed_all$QM,2),format='f',digits=2), ", df ", mixed_all$m, "), p = ", formatC(round(mixed_all$QMp,3),format='f',digits=3),
"; Residual heterogeneity (Qe ", formatC(round(mixed_all$QE,2),format='f',digits=2), ", df ", mixed_all$k-mixed_all$p, "), p < 0.0001"),
footnote_x_main, footnote_y_main, gp = gpar(fontsize=12, font = "sans")) }
if (nrow(data_all)>=min & n_vaccines==1 & meta_all$QEp>=0.0001) {
grid.text(paste0("Heterogeneity (Q ", formatC(round(meta_all$QE,2),format='f',digits=2), ", df ", meta_all$k-meta_all$p, "), p = ", formatC(round(meta_all$QEp,3),format='f',digits=3)),
footnote_x_main, footnote_y_main, gp = gpar(fontsize=12, font = "sans")) }
if (nrow(data_all)>=min & n_vaccines==1 & meta_all$QEp<0.0001) {
grid.text(paste0("Heterogeneity (Q ", formatC(round(meta_all$QE,2),format='f',digits=2), ", df ", meta_all$k-meta_all$p, "), p < 0.0001"),
footnote_x_main, footnote_y_main, gp = gpar(fontsize=12, font = "sans")) }
} else { print("Insufficient studies (n<2)") }
```
### Funnel plot
```{r, echo=FALSE, message=FALSE, fig.height=3, fig.width=6}
# Draw funnel plot containing all results included in meta-analysis
overall_estimate = meta_all$b
funnel_input = data.frame(SE = sqrt(meta_all$vi), LogRR = meta_all$yi, Vaccine = input_all$Vaccine, N = input_all$Total)
ggplot(funnel_input, aes(y=SE, x=LogRR)) + geom_point(aes(color = Vaccine), size=3.5, alpha=0.7) +
geom_vline(xintercept=overall_estimate, color='grey', linetype='dashed') + theme_minimal() +
ylab('SE (log RR)') + xlab('log RR') + scale_y_reverse() + xlim(-2,2) +
scale_color_manual(values = c("Cholera" = "#90B11F", "Polio" = "#F1A44F" , "Rotavirus" = "#D43E55")) +
theme(legend.title=element_blank(), legend.position="right")
```
### Egger's test
```{r, echo=FALSE, message=FALSE, warning=FALSE}
# Perform Egger's test; for 'RVV separated from OPV', this should be stratified by vaccine type to account for replication of infants for RVV and OPV outcomes
if (nrow(data_all)<3) { print("Insufficient studies (n<3)") }
if (nrow(data_all)>=3 & intervention!="RVV separated from OPV" & mixed_all$QMp>=0.05) {
print("No replication of infants across vaccines or significant vaccine effect, therefore combined test performed")
regtest(meta_all, predictor="sei") }
if (nrow(data_all)>=3 & (intervention=="RVV separated from OPV" | mixed_all$QMp<0.05)) {
print("Infants replicated across vaccines or vaccine effect significant, therefore separate tests performed")
print("Cholera:")
if (nrow(input_cholera)>=3) { print(regtest(meta_cholera, predictor="sei")) } else { print("Insufficient studies (n<3)")}
print("Rotavirus:")
if (nrow(input_rota)>=3) { print(regtest(meta_rota, predictor="sei")) } else { print("Insufficient studies (n<3)")}
print("OPV3:")
if (nrow(input_PV3)>=3) { print(regtest(meta_PV3, predictor="sei")) } else { print("Insufficient studies (n<3)")}
}
```
### Meta-analysis output
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (nrow(input_all)>=min) { summary(meta_all) } else { print("Insufficient studies (n<2)") }
```
### Meta-regression output
```{r, echo=FALSE, message=FALSE, warning=FALSE}
# If more than one type of vaccine included in analysis, print meta-regression results
if (nrow(data_all)>=min & n_vaccines>1) { mixed_all } else { print("Insufficient studies for meta-regression (either <2 studies or only 1 vaccine type)") }
```
### Intervention-specific outputs
#### Summary of cholera studies
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (nrow(input_cholera)>=min) { summary(meta_cholera) } else { print("Insufficient studies (n<2)")}
```
#### Summary of rotavirus studies
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (nrow(input_rota)>=min) { summary(meta_rota) } else { print("Insufficient studies (n<2)")}
```
#### Summary of PV3 studies
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (nrow(input_PV3)>=min) { summary(meta_PV3) } else { print("Insufficient studies (n<2)")}
```
### Meta-regression: secondary moderators
#### Age group
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (nrow(data_all)>=min & n_vaccines>1) { QEp = mixed_all$QEp }
if (nrow(data_all)>=min & n_vaccines==1) { QEp = meta_all$QEp }
if (QEp>0.05) { print("Residual heterogeneity not significant (p>0.05)")
} else if (nlevels(factor(data_all$Age_group))==1) { print("No variation in moderator among studies")
} else if (nlevels(factor(data_all$Age_group))==nrow(data_all)) { print("Insufficient studies (n studies == n moderators)")
} else if (intervention=="RVV separated from OPV") {
print("Rotavirus-specific analysis performed owing to absence of significant residual heterogeneity for OPV studies")
print(table(data_rota$Age_group))
meteregression_age = rma.mv(yi, vi, mods = ~ factor(Age_group), data = data_rota, method = "REML")
meteregression_age
} else if (intervention!="RVV separated from OPV") {
print(table(data_all$Age_group))
meteregression_age = rma(yi, vi, mods = ~ factor(Age_group), data = data_all, method = "REML")
meteregression_age
}
```
#### Income setting
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (QEp>0.05) { print("Residual heterogeneity not significant (p>0.05)")
} else if (nlevels(factor(data_all$Income_group))==1) { print("No variation in moderator among studies")
} else if (nlevels(factor(data_all$Income_group))==nrow(data_all)) { print("Insufficient studies (n studies == n moderators)")
} else if (intervention=="RVV separated from OPV") {
print("Rotavirus-specific analysis performed owing to absence of significant residual heterogeneity for OPV studies")
print(table(data_rota$Income_group))
meteregression_setting = rma.mv(yi, vi, mods = ~ factor(Income_group), data = data_rota, method = "REML")
meteregression_setting
} else if (intervention!="RVV separated from OPV") {
print(table(data_all$Income_group))
meteregression_setting = rma(yi, vi, mods = ~ factor(Income_group), data = data_all, method = "REML")
meteregression_setting
}
```
#### Background immunogenicity (seroconversion rate in the control group)
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (QEp>0.05) { print("Residual heterogeneity not significant (p>0.05)")
} else if (intervention=="RVV separated from OPV") {
print("Rotavirus-specific analysis performed owing to absence of significant residual heterogeneity for OPV studies")
meteregression_baseline = rma.mv(yi, vi, mods = ~ asin(sqrt(Baseline_seroconversion)), data = data_rota, method = "REML")
meteregression_baseline
} else if (intervention!="RVV separated from OPV") {
meteregression_baseline = rma(yi, vi, mods = ~ asin(sqrt(Baseline_seroconversion)), data = data_all, method = "REML")
meteregression_baseline
}
```
## OPV-specific analysis
```{r, echo=FALSE, message=FALSE, warning=FALSE}
# Calculate sums of N by vaccine
PV1_sum = sum(input_PV_all$Total[input_PV_all$Measure_of_SC=="OPV1 N-AB"])
PV2_sum = sum(input_PV_all$Total[input_PV_all$Measure_of_SC=="OPV2 N-AB"])
PV3_sum = sum(input_PV_all$Total[input_PV_all$Measure_of_SC=="OPV3 N-AB"])
overall_PV_sum = sum(input_PV_all$Total)
# Calculate number of vaccines included in analysis
n_PV_vaccines = as.numeric(PV1_sum>0) + as.numeric(PV2_sum>0) + as.numeric(PV3_sum>0)
# Calculate summary statistics for each subset
if (PV1_sum>0) {data_PV1 = escalc(measure = "RR", ai = Int_SC_n, bi = Int_N-Int_SC_n, ci = Ctrl_SC_n, di = Ctrl_N-Ctrl_SC_n, data = input_PV1, append = TRUE) }
if (PV2_sum>0) {data_PV2 = escalc(measure = "RR", ai = Int_SC_n, bi = Int_N-Int_SC_n, ci = Ctrl_SC_n, di = Ctrl_N-Ctrl_SC_n, data = input_PV2, append = TRUE) }
if (PV3_sum>0) {data_PV3 = escalc(measure = "RR", ai = Int_SC_n, bi = Int_N-Int_SC_n, ci = Ctrl_SC_n, di = Ctrl_N-Ctrl_SC_n, data = input_PV3, append = TRUE) }
if (overall_PV_sum>0) {data_PV_all = escalc(measure = "RR", ai = Int_SC_n, bi = Int_N-Int_SC_n, ci = Ctrl_SC_n, di = Ctrl_N-Ctrl_SC_n, data = input_PV_all, append = TRUE) }
# Perform REML meta-analyses
if (PV1_sum>0) { meta_PV1 = rma(yi, vi, data = data_PV1, method = "REML") }
if (PV2_sum>0) { meta_PV2 = rma(yi, vi, data = data_PV2, method = "REML") }
if (PV3_sum>0) { meta_PV3 = rma(yi, vi, data = data_PV3, method = "REML") }
# Perform combined meta-analysis, including random effect on study ID
if (overall_PV_sum>0) { meta_PV_all = rma.mv(yi, vi, data = data_PV_all, method = "REML", random = ~ 1 | Reference) }
# Perform mixed-effects meta-regression, including random effect on study ID
if (nrow(input_PV_all)>=min & n_PV_vaccines>1) { mixed_PV_all = rma.mv(yi, vi, mods = ~ Measure_of_SC, data = data_PV_all, method = "REML", random = ~ 1 | Reference) }
if (n_PV_vaccines==1) {
mixed_PV_all = NA
mixed_PV_all$QEp = mixed_PV_all$QMp = 1 } # if there is only 1 vaccine type, assign arbitrary value of 1 to mixed_all p values so as to avoid errors in later logical operators
# Create function to collate relevant data for each column of PV-specific forest plot
table_column_PV = function(column_title, ref) {
column = column_title # specify column title
if (nrow(input_PV1)>0) { column = c(column,NA,input_PV1[,ref]) } # add study-specific rows if there is at least one study
if (nrow(input_PV1)<min & nrow(input_PV1)>0) { column = c(column,NA) } # add gap if number of studies is <min
if (nrow(input_PV1)>=min) { column = c(column,NA,NA) } # add summary row if number of studies is >=min
if (nrow(input_PV2)>0) { column = c(column,NA,input_PV2[,ref]) }
if (nrow(input_PV2)<min & nrow(input_PV2)>0) { column = c(column,NA) }
if (nrow(input_PV2)>=min) { column = c(column,NA,NA) }
if (nrow(input_PV3)>0) { column = c(column,NA,input_PV3[,ref]) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { column = c(column,NA) }
if (nrow(input_PV3)>=min) { column = c(column,NA,NA) }
if (nrow(input_PV_all)>=min & n_PV_vaccines>1) { column = c(column,NA) }
if (nrow(input_PV_all)>=min & n_PV_vaccines==1) { column = column[-length(column)] }
return(column)
}
# Use function to create meta-data columns for forest plot
country = table_column_PV(column_title="Country", ref="Country")
age = table_column_PV(column_title="Age (m)", ref="Age_formatted")
vaccine = table_column_PV(column_title="Vaccine", ref="Vaccine_formatted")
intervention_col = table_column_PV(column_title="Intervention", ref="Intervention_formatted")
N_int = table_column_PV(column_title="n/N (%)", ref="Int_SC_full")
control = table_column_PV(column_title="Control", ref="Control_formatted")
N_ctrl = table_column_PV(column_title="n/N (%)", ref="Ctrl_SC_full")
# Create first column composed of Study IDs and vaccine names
titles = "Study"
if (nrow(input_PV1)>0) { titles = c(titles,"OPV1",input_PV1$Reference) }
if (nrow(input_PV1)<min & nrow(input_PV1)>0) { titles = c(titles,NA) }
if (nrow(input_PV1)>=min) { titles = c(titles,"Summary",NA) }
if (nrow(input_PV2)>0) { titles = c(titles,"OPV2",input_PV2$Reference) }
if (nrow(input_PV2)<min & nrow(input_PV2)>0) { titles = c(titles,NA) }
if (nrow(input_PV2)>=min) { titles = c(titles,"Summary",NA) }
if (nrow(input_PV3)>0) { titles = c(titles,"OPV3",input_PV3$Reference) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { titles = c(titles,NA) }
if (nrow(input_PV3)>=min) { titles = c(titles,"Summary",NA) }
if (nrow(input_PV_all)>=min & n_PV_vaccines>1) { titles = c(titles, "Overall") }
if (nrow(input_PV_all)>=min & n_PV_vaccines==1) { titles = titles[-length(titles)] }
# Create final column composed of RRs and 95% CIs
RRs = "RR (95% CI)"
if (nrow(input_PV1)>0) { RRs = c(RRs,NA,RR_CIs(meta_PV1)) }
if (nrow(input_PV1)<min & nrow(input_PV1)>0) { RRs = c(RRs,NA) }
if (nrow(input_PV1)>=min) { RRs = c(RRs,RR_summary(meta_PV1),NA) }
if (nrow(input_PV2)>0) { RRs = c(RRs,NA,RR_CIs(meta_PV2)) }
if (nrow(input_PV2)<min & nrow(input_PV2)>0) { RRs = c(RRs,NA) }
if (nrow(input_PV2)>=min) { RRs = c(RRs,RR_summary(meta_PV2),NA) }
if (nrow(input_PV3)>0) { RRs = c(RRs,NA,RR_CIs(meta_PV3)) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { RRs = c(RRs,NA) }
if (nrow(input_PV3)>=min) { RRs = c(RRs,RR_summary(meta_PV3),NA) }
if (nrow(input_PV_all)>=min & n_PV_vaccines>1) { RRs = c(RRs,RR_summary(meta_PV_all)) }
if (nrow(input_PV_all)>=min & n_PV_vaccines==1) { RRs = RRs[-length(RRs)] }
# Collate forest plot text
tabletext = cbind(titles, country, age, vaccine, intervention_col, N_int, control, N_ctrl, RRs)
# Create variable composed of RRs
m = NA
if (nrow(input_PV1)>0) { m = c(m,NA,meta_PV1$yi) }
if (nrow(input_PV1)<min & nrow(input_PV1)>0) { m = c(m,NA) }
if (nrow(input_PV1)>=min) { m = c(m,meta_PV1$b,NA) }
if (nrow(input_PV2)>0) { m = c(m,NA,meta_PV2$yi) }
if (nrow(input_PV2)<min & nrow(input_PV2)>0) { m = c(m,NA) }
if (nrow(input_PV2)>=min) { m = c(m,meta_PV2$b,NA) }
if (nrow(input_PV3)>0) { m = c(m,NA,meta_PV3$yi) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { m = c(m,NA) }
if (nrow(input_PV3)>=min) { m = c(m,meta_PV3$b,NA) }
if (nrow(input_PV_all)>=min & n_PV_vaccines>1) { m = c(m,meta_PV_all$b) }
if (nrow(input_PV_all)>=min & n_PV_vaccines==1) { m = m[-length(m)] }
# Create variables for lower CI limits of RR estimates
l = NA
if (nrow(input_PV1)>0) { l = c(l,NA,meta_PV1$yi-sqrt(meta_PV1$vi)*1.96) }
if (nrow(input_PV1)<min & nrow(input_PV1)>0) { l = c(l,NA) }
if (nrow(input_PV1)>=min) { l = c(l,meta_PV1$b-meta_PV1$se*1.96,NA) }
if (nrow(input_PV2)>0) { l = c(l,NA,meta_PV2$yi-sqrt(meta_PV2$vi)*1.96) }
if (nrow(input_PV2)<min & nrow(input_PV2)>0) { l = c(l,NA) }
if (nrow(input_PV2)>=min) { l = c(l,meta_PV2$b-meta_PV2$se*1.96,NA) }
if (nrow(input_PV3)>0) { l = c(l,NA,meta_PV3$yi-sqrt(meta_PV3$vi)*1.96) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { l = c(l,NA) }
if (nrow(input_PV3)>=min) { l = c(l,meta_PV3$b-meta_PV3$se*1.96,NA) }
if (nrow(input_PV_all)>=min & n_PV_vaccines>1) { l = c(l,meta_PV_all$b-meta_PV_all$se*1.96) }
if (nrow(input_PV_all)>=min & n_PV_vaccines==1) { l = l[-length(l)] }
# Create variables for upper CI limits of RR estimates
u = NA
if (nrow(input_PV1)>0) { u = c(u,NA,meta_PV1$yi+sqrt(meta_PV1$vi)*1.96) }
if (nrow(input_PV1)<min & nrow(input_PV1)>0) { u = c(u,NA) }
if (nrow(input_PV1)>=min) { u = c(u,meta_PV1$b+meta_PV1$se*1.96,NA) }
if (nrow(input_PV2)>0) { u = c(u,NA,meta_PV2$yi+sqrt(meta_PV2$vi)*1.96) }
if (nrow(input_PV2)<min & nrow(input_PV2)>0) { u = c(u,NA) }
if (nrow(input_PV2)>=min) { u = c(u,meta_PV2$b+meta_PV2$se*1.96,NA) }
if (nrow(input_PV3)>0) { u = c(u,NA,meta_PV3$yi+sqrt(meta_PV3$vi)*1.96) }
if (nrow(input_PV3)<min & nrow(input_PV3)>0) { u = c(u,NA) }
if (nrow(input_PV3)>=min) { u = c(u,meta_PV3$b+meta_PV3$se*1.96,NA) }
if (nrow(input_PV_all)>=min & n_PV_vaccines>1) { u = c(u,meta_PV_all$b+meta_PV_all$se*1.96) }
if (nrow(input_PV_all)>=min & n_PV_vaccines==1) { u = u[-length(u)] }
```
### Forest plot
```{r, echo=FALSE, message=FALSE, warning=FALSE, fig.width=plot_width_polio, fig.height=plot_height_polio}
# Create function to assign colours to meta-analysis boxes and lines
# Adapted from: https://stackoverflow.com/questions/46938910
fn <- local({
i = 0
b_clrs = vector()
if (nrow(input_PV1)>0) { b_clrs = rep("#f1cd4f", nrow(input_PV1)) }
if (nrow(input_PV2)>0) { b_clrs = c(b_clrs, rep("#734109", nrow(input_PV2))) }
if (nrow(input_PV3)>0) { b_clrs = c(b_clrs, rep("#F1A44F", nrow(input_PV3))) }
b_clrs = c(b_clrs, "black")
l_clrs = rep("grey", length(b_clrs))
# l_clrs = b_clrs # use this line instead of the line above to make lines the same colour as the boxes
function(..., clr.line, clr.marker){
i <<- i + 1
fpDrawNormalCI(..., clr.line = l_clrs[i], clr.marker = b_clrs[i])
}
})
# Create function to assign colours to meta-analysis summary diamonds
# Adapted from: https://stackoverflow.com/questions/46938910
fn_sum <- local({
i = 0
b_clrs_sum = vector()
if (nrow(input_PV1)>=min) { b_clrs_sum = "#f1cd4f" }
if (nrow(input_PV2)>=min) { b_clrs_sum = c(b_clrs_sum, "#734109") }
if (nrow(input_PV3)>=min) { b_clrs_sum = c(b_clrs_sum, "#F1A44F") }
b_clrs_sum = c(b_clrs_sum, "black")
function(..., col){
i <<- i + 1
fpDrawSummaryCI(..., col = b_clrs_sum[i])
}
})
# Create forest plot
if (nrow(input_PV_all)>=min) {
forestplot(tabletext,exp(m),exp(l),exp(u),zero=1,
is.summary=c(TRUE,TRUE,!is.na(tabletext[3:nrow(tabletext),1]) & (tabletext[3:nrow(tabletext),1]=="Summary" | tabletext[3:nrow(tabletext),1]=="Overall"| tabletext[3:nrow(tabletext),1]=="OPV1"| tabletext[3:nrow(tabletext),1]=="OPV2"| tabletext[3:nrow(tabletext),1]=="OPV3")),
clip=c(forest_x_min_polio,forest_x_max_polio), xlog=TRUE,
xticks=c(forest_x_min_polio,1,forest_x_max_polio),
fn.ci_norm=fn,
fn.ci_sum=fn_sum,
colgap=unit(5,"mm"),
txt_gp = fpTxtGp(ticks = gpar(cex=0.8))
)
# Add footnote containing heterogeneity results
if (nrow(input_PV_all)>=min & n_PV_vaccines>1 & mixed_PV_all$QEp>=0.0001) {
grid.text(paste0("Heterogeneity among vaccines (Qm ", formatC(round(mixed_PV_all$QM,2),format='f',digits=2), ", df ", mixed_PV_all$m, "), p = ", formatC(round(mixed_PV_all$QMp,3),format='f',digits=3),
"; Residual heterogeneity (Qe ", formatC(round(mixed_PV_all$QE,2),format='f',digits=2), ", df ", mixed_PV_all$k-mixed_PV_all$p, "), p = ", formatC(round(mixed_PV_all$QEp,3),format='f',digits=3)),
footnote_x_polio, footnote_y_polio, gp = gpar(fontsize=12, font = "sans")) }
if (nrow(input_PV_all)>=min & n_PV_vaccines>1 & mixed_PV_all$QEp<0.0001) {
grid.text(paste0("Heterogeneity among vaccines (Qm ", formatC(round(mixed_PV_all$QM,2),format='f',digits=2), ", df ", mixed_PV_all$m, "), p = ", formatC(round(mixed_PV_all$QMp,3),format='f',digits=3),
"; Residual heterogeneity (Qe ", formatC(round(mixed_PV_all$QE,2),format='f',digits=2), ", df ", mixed_PV_all$k-mixed_PV_all$p, "), p < 0.0001"),
footnote_x_polio, footnote_y_polio, gp = gpar(fontsize=12, font = "sans")) }
if (nrow(input_PV_all)>=min & n_PV_vaccines==1 & meta_PV_all$QEp>=0.0001) {
grid.text(paste0("Heterogeneity (Q ", formatC(round(meta_PV_all$QE,2),format='f',digits=2), ", df ", meta_PV_all$k-meta_PV_all$p, "), p = ", formatC(round(meta_PV_all$QEp,3),format='f',digits=3)),
0.1, footnote_y_polio, gp = gpar(fontsize=12, font = "sans")) }
if (nrow(input_PV_all)>=min & n_PV_vaccines==1 & meta_PV_all$QEp<0.0001) {
grid.text(paste0("Heterogeneity (Q ", formatC(round(meta_PV_all$QE,2),format='f',digits=2), ", df ", meta_PV_all$k-meta_PV_all$p, "), p < 0.0001"),
0.1, footnote_y_polio, gp = gpar(fontsize=12, font = "sans")) }
} else { print("Insufficient studies (n<2)")}
```
### Funnel plot
```{r, echo=FALSE, message=FALSE, warning=FALSE, fig.height=3, fig.width=6}
# Draw funnel plot containing all results included in meta-analysis
if (overall_PV_sum>0) {
overall_estimate = meta_PV_all$b
funnel_input = data.frame(SE = sqrt(meta_PV_all$vi), LogRR = meta_PV_all$yi,
Vaccine = substr(input_PV_all$Measure_of_SC,0,4), N = input_PV_all$Total, Study = input_PV_all$Reference)
ggplot(funnel_input, aes(y=SE, x=LogRR)) + geom_point(aes(color = Vaccine), size=3.5, alpha=0.7) +
geom_vline(xintercept=overall_estimate, color='grey', linetype='dashed') + theme_minimal() +
ylab('SE (log RR)') + xlab('log RR') + scale_y_reverse() + xlim(-2,2) +
scale_color_manual(values = c("OPV1" = "#f1cd4f", "OPV2" = "#734109" , "OPV3" = "#F1A44F")) +
theme(legend.title=element_blank(), legend.position="right")
} else { print("Insufficient studies (n<2)")}
```
### Egger's test
Infants replicated across vaccines, therefore separate tests performed
```{r, echo=FALSE, message=FALSE, warning=FALSE}
# Perform Egger's test; this should be stratified by vaccine type to account for replication of infants across PV serotypes
print("OPV1:")
if (nrow(input_PV1)>=3) { print(regtest(meta_PV1, predictor="sei")) } else { print("Insufficient studies (n<3)")}
print("OPV2:")
if (nrow(input_PV2)>=3) { print(regtest(meta_PV2, predictor="sei")) } else { print("Insufficient studies (n<3)")}
print("OPV3:")
if (nrow(input_PV3)>=3) { print(regtest(meta_PV3, predictor="sei")) } else { print("Insufficient studies (n<3)")}
```
### Meta-analysis output
```{r, echo=FALSE, message=TRUE, warning=TRUE}
if (nrow(input_PV_all)>=min) { summary(meta_PV_all) } else { print("Insufficient studies (n<2)")}
```
### Meta-regression output
```{r, echo=FALSE, message=FALSE, warning=FALSE}
# If more than one type of vaccine included in analysis, print meta-regression results
if (nrow(input_PV_all)>=min & n_PV_vaccines>1) { mixed_PV_all } else { print("Insufficient studies for meta-regression (either <2 studies or only 1 vaccine type)") }
```
### Serotype-specific outputs
#### Summary of PV1 studies
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (nrow(input_PV1)>=min) { summary(meta_PV1) } else { print("Insufficient studies (n<2)")}
```
#### Summary of PV2 studies
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (nrow(input_PV2)>=min) { summary(meta_PV2) } else { print("Insufficient studies (n<2)")}
```
#### Summary of PV3 studies
```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (nrow(input_PV3)>=min) { summary(meta_PV3) } else { print("Insufficient studies (n<2)")}
```