Function Subroutine : Boolean

I am using an if statement in my procedure that calls upon my Boolean function; however, when I run the program, it always outputs the message as if the function were true.

Public Function INR() As Boolean
    If Avg < 1.5 & SD < 0.5 Then
        INR = True
    Else
        INR = False
    End If
End Function

Public Sub PatientINR()
    Range("B2", Range("B1").End(xlDown)).Name = "Name"
    Dim cell As Range, reply As String, i As Long, x As Variant, Avg As Long, SD As Long
    reply = InputBox("Enter patient's name", "INR", "Madelyn Carberry")
        i = 1
    x = Range("Name").Cells(i)
    Do Until x = reply
        i = i + 1
        x = Range("Name").Cells(i)
    Loop
    Avg = Range("Name").Cells(i, 17)
    SD = Range("Name").Cells(i, 18)
    Call INR
    If INR = True Then
        MsgBox reply & "'s INR record is satisfactory for the procedure"
    End If
    If INR = False Then
        MsgBox reply & "'s INR record is not satisfactory for the procedure"
    End If

End Sub