Skip to contents

BayesOutbreak: the Bayes outbreak detector of surveillance::algo.bayes. CusumSurveillance: CUSUM of standardised counts (algo.cusum); with expected counts per region the spatial surveillance CUSUM. EcologicalRegression: Poisson, negative binomial and zero-inflated Poisson regression with expected-count offsets. LerouxPrecision and Bym2Structure: Leroux and BYM2 area-effect structures. BufferExposure and KernelExposure: exposure assessment. Identical to the Python arm morie.fn.episurv.

Usage

BayesOutbreak(
  observed,
  freq = 52,
  b = 0,
  w = 6,
  act_y = TRUE,
  alpha = 0.05,
  time_points = NULL
)

CusumSurveillance(
  observed,
  expected = NULL,
  start = NULL,
  k = 1.04,
  h = 2.26,
  trans = "standard",
  reset = FALSE
)

EcologicalRegression(
  counts,
  expected,
  X = NULL,
  family = "poisson",
  Z = NULL,
  tol = 1e-12,
  maxit = 500
)

LerouxPrecision(A, rho, tau = 1)

Bym2Structure(A, tau = 1, phi = 0.5, tol = 1e-10)

BufferExposure(
  receptors,
  sources,
  radius,
  weights = NULL,
  metric = "euclidean"
)

KernelExposure(
  receptors,
  sources,
  bandwidth,
  weights = NULL,
  kernel = "gaussian"
)

Arguments

observed

Counts (vector, or times by regions matrix).

freq

Observations per year.

b

Number of past years.

w

Half-window width.

act_y

Use the preceding w counts.

alpha

Test level.

time_points

1-based time points to evaluate.

expected

Expected counts (same shape as observed).

start

First monitored time point when no expected counts are given.

k, h

CUSUM reference value and threshold.

trans

"standard", "rossi", "anscombe" or "none".

reset

Reset the sum after an alarm.

counts

Area counts.

X

Area covariates (no intercept).

family

"poisson", "negbin" or "zip".

Z

Zero-inflation covariates (no intercept).

tol, maxit

Convergence controls.

A

Symmetric adjacency matrix.

rho

Leroux spatial parameter.

tau

Precision.

phi

Share of structured variance.

receptors, sources

Coordinates (rows).

radius

Buffer radius.

weights

Source weights.

metric

"euclidean" or "haversine".

bandwidth

Kernel bandwidth.

kernel

"gaussian" or "quartic".

Value

A list or vector.

References

Hoehle, M. (2007). surveillance: an R package for the monitoring of infectious diseases. Computational Statistics 22, 571-582.

Rogerson, P. A. and Yamada, I. (2004). Approaches to syndromic surveillance when data consist of small regional counts. MMWR 53, 79-85.

Lambert, D. (1992). Zero-inflated Poisson regression. Technometrics 34, 1-14.

Leroux, B. G., Lei, X. and Breslow, N. (2000). Estimation of disease rates in small areas: a new mixed model for spatial dependence. Springer, 179-191.

Riebler, A., Sorbye, S. H., Simpson, D. and Rue, H. (2016). An intuitive Bayesian spatial model for disease mapping that accounts for scaling. Statistical Methods in Medical Research 25, 1145-1165.

Examples

BayesOutbreak(c(3, 5, 2, 4, 6, 3, 4, 12), w = 6, time_points = 8)$alarm
#> [1] TRUE
LerouxPrecision(rbind(c(0, 1, 0), c(1, 0, 1), c(0, 1, 0)), 0.5, 2)
#>      [,1] [,2] [,3]
#> [1,]    2   -1    0
#> [2,]   -1    3   -1
#> [3,]    0   -1    2