使用heemod构建三状态马尔可夫模型时define_strategy报错求助

报错原因 #

define_strategy()要求transition参数必须是heemod专属的转移对象，而非普通R矩阵。直接传入原生matrix时，函数无法解析其中的状态元数据，因此判定转移对象的状态数为0，与你定义的3个状态产生数量不匹配的错误。

解决方法 #

使用heemod的define_transition()函数将你的转移矩阵包装为符合要求的转移对象，再传入define_strategy()即可。

修改后的完整代码 #

library(heemod)

params <- define_parameters(
  cost_healthy = 80000,
  cost_state2 = 300000,
  cost_death = 0,
  util_healthy = 0.95,
  util_state2 = 0.70,
  util_death = 0.00
)

transition_matrix <- matrix(c(
  0.90, 0.08, 0.02,
  0.00, 0.93, 0.07,
  0.00, 0.00, 1.00
), nrow = 3, byrow = TRUE,
dimnames = list(
  from = c("Healthy", "State2", "Death"),
  to   = c("Healthy", "State2", "Death")
))

# 用define_transition包装转移矩阵
trans_mat <- define_transition(transition_matrix)

state_healthy <- define_state(cost = cost_healthy, qaly = util_healthy)
state_state2 <- define_state(cost = cost_state2, qaly = util_state2)
state_death <- define_state(cost = cost_death, qaly = util_death)

strategy <- define_strategy(
  transition = trans_mat,  # 使用包装后的转移对象
  Healthy = state_healthy,
  State2 = state_state2,
  Death = state_death
)

内容的提问来源于stack exchange，提问作者福井里佳