Table 2.

Methodological quality assessment of studies using the Newcastle-Ottawa Scale

Cohort studies
Study	Representativeness of the exposed cohort	Selection of the nonexposed cohort	Ascertainment of the exposure	Demonstration that outcome of interest was not present at start of study	Comparability	Assessment of outcome	Follow-up long enough	Follow-up adequacy
Jeon	*Truly representative	*Same community as exposed cohort	*Secure record	No	**Age and sex	*Independent assessment	*Yes	No statement
Hao	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	**Age and sex	*Independent assessment	*Yes	No statement
Midha a	*Somewhat representative	*Same community as exposed cohort	*Secure record	*Yes	**Age and sex	*Independent assessment	*Yes	*Yes
Ueda	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	*Age	*Independent assessment	*Yes	No statement
Wang	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	**Age and sex	*Independent assessment	*Yes	*Yes
Zheng	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	*Age	*Independent assessment	*Yes	*Yes
Talamini	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	**Age and sex	*Independent assessment	*Yes	*Yes
Chari	*Truly representative	*Same community as exposed cohort	*Secure record	No	**Age and sex	*Independent assessment	*Yes	*Yes
Malka	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	**Age and sex	*Independent assessment	*Yes	No
Lowenfels (CP)	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	**Age and sex	*Independent assessment	*Yes	No
Pedrazzoli	*Somewhat representative	*Same community as exposed cohort	*Secure record	*Yes	*Age	*Independent assessment	*Yes	*Yes
Rocca	*Truly representative	*Same community as exposed cohort	*Secure record	No	**Age and sex	*Independent assessment	*Yes	No statement
Hirano	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	**Age and sex	*Independent assessment	*Yes	No statement
Hamoir	*Truly representative	*Same community as exposed cohort	*Secure record	No	*Age	*Independent assessment	*Yes	*Yes
Rebours	*Truly representative	*Same community as exposed cohort	*Secure record	No	**Age and sex	*Independent assessment	*Yes	No statement
Howes	*Truly representative	*Same community as exposed cohort	*Secure record	No	**Age and sex	*Independent assessment	*Yes	No statement
Lowenfels (HP)	*Truly representative	*Same community as exposed cohort	*Secure record	*Yes	**Age and sex	*Independent assessment	*Yes	No statement

Single-arm cohort studies
Study	Selection	Adequate ascertainment of exposure	Adequate ascertainment of outcome	Follow-up long enough?	Replication/Inferences
Rijkers a	*Truly representative	*Yes	No	No	*Yes
Rijkers b	*Truly representative	*Yes	*Yes	*Yes	*Yes
Sakorafas	*Somewhat representative	*Yes	*Yes	No	*Yes
Agarwal	*Truly representative	*Yes	No	*Yes	*Yes
Dite	Unclear	No description	No	*Yes	No
Ikeura	*Truly representative	*Yes	*Yes	*Yes	*Yes
Gupta	*Truly representative	*Yes	*Yes	*Yes	*Yes
Vujasinovic	*Truly representative	*Yes	*Yes	*Yes	*Yes

Case-control studies
Study	Is case definition adequate?	Representativeness of the cases	Selection of controls	Definition of controls	Comparability	Ascertainment of exposure	Same method for ascertainment for cases and controls
Midha b	*Yes, with independent validation	*Consecutive or obviously representative series of cases	*Community controls	No mention	**Age, sex, and socioeconomic status	*Secure record	No
Hart	*Yes, with independent validation	*Consecutive or obviously representative series of cases	*Community controls	No mention	**Age, sex, and registration date	*Secure record	No

CP, chronic pancreatitis; HP, hereditary pancreatitis. *denotes 1 point, and ** denotes 2 points.