assembly lea: invalid effective address

I'm getting this kind of error:

beroset-p-637-invalid effective address

Here's a sample code block that contains the error line:

mov eax, 3
mov ebx, 0
lea ecx, [record + count*patient + firstName]          ;this one
int 80h

Here are my variables from the code block above:

patient equ 37
firstName equ 0

count resb 1
record resb patient*5

can't the count variable be used in multiplying with the patient?

I'm using NASM in x86 Ubuntu 13